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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies. 

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage. 

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

  • Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
  • Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
  • The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
  • Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

 Example: car
 Result: Any document containing that word.

Multiple word search

 Example: car seat requirements
 Result: Any document containing any of these words.

Connector word search

 Example: car AND seat AND requirements
 Result: Any document containing all of these words.

 Note: Search operators such as AND or OR must be in all capital letters.

Phrase in double quotes

 Example: "headlamp function"
 Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

Not

Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”). 

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

Search Tool

NHTSA's Interpretation Files Search



Displaying 11931 - 11940 of 16490
Interpretations Date

ID: nht93-3.5

Open

DATE: April 19, 1993

FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA

TO: Scott R. Dennison -- Vice-President, Production, Excalibur Automobile Corporation

TITLE: None

ATTACHMT: Attached to letter dated 3-12-93 from Scott R. Dennison to Robert Hellmuth

TEXT: Robert Hellmuth, Director of the Office of Vehicle Safety Compliance, has asked us to respond to your FAX of March 12, 1993. You offer your input and assistance "regarding the alleged debate over the treatment of vehicles replicating pre-safety standard vehicle designs and their compliance with current Federal Motor Vehicle Safety Standards."

We are unsure what you mean by "debate." Under the National Traffic and Motor Vehicle Safety Act, all new motor vehicles, including replica vehicles, must conform to the Safety Standards unless exempted by the Administrator from one or more of those standards pursuant to 49 CFR Part 555. This regulation has been in effect since 1972, and is intended to assist temporarily those manufacturers whose products may differ from those of conventional motor vehicles. I should note that the predecessor owners of Excalibur have been able to certify compliance of this replica vehicle since 1972 with all Safety Standards without seeking a temporary exemption from them.

However, the Safety Standards do not cover a vehicle in use. Occasionally, situations arise in which a vehicle is newly manufactured, but contains a substantial number of parts from a vehicle previously in use. In these instances the question arises whether the vehicle may be considered "new" and required to comply with the Safety Standards, or one that may be regarded as having been a vehicle in use for which compliance is not required. Perhaps this is the "debate" to which you refer. We handle these situations according to the facts of each.

If you wish to offer further comments, we would be pleased to consider them.

ID: nht93-8.17

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: James E. Walker -- Manager, LSI Laboratories, Lighting Sciences, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 10/4/93 from James E. Walker to John Womack

TEXT:

We are replying to your letter of October 4, 1993, with respect to the requirements of Federal Motor Vehicle Safety Standard No. 108 for taillamps.

You believe that a discrepancy exists because paragraph S5.1.1 "requires equipment to be designed to Tables I, II (you mean III), and S7, which references SAE J585e for the Tail lamp," whereas paragraph S5.1.1.11 "requires Table 1 of this specification to be substituted for the values achieved by Figures 1a and 1b, and in addition, to substitute Table 1 of SAE J585e by the values achieved by multiplying the percentages of Figure 1a by Table 1 and 3 of SAE J588 NOV84 Turn Signal Lamps."

You assume that the photometric requirements are those of Figure 1a, 1b, and 1c. Your assumption is correct. However, there is no discrepancy in the standard. The requirements for motor vehicle lighting equipment are set forth in section S5. Paragraph S5.1.1 requires lighting equipment to comply with the SAE materials contained in the tables, except as may be provided in succeeding paragraphs of Paragraph S5.1.1. Tables I and III incorporate by reference SAE Standard J585e, Tail Lamps, September 1977. However, on March 3, 1993, NHTSA redesignated Paragraph S5.1.1.11 (with references to Figures 1a and 1b) as S5.1.1.6, and revised it to include, among other things, the reference in paragraph S5.1.1.12 to Figure 1c. The same notice removed paragraph S5.1.1.12 from the standard. New Paragraph S5.1.1.6 states that instead of the photometric values specified in Table 1 of SAE J585e, taillamps shall comply with those of Figures 1a, 1b, and 1c.

I enclose a copy of the amendment for your information, and hope that this answers your question.

ID: nht94-7.29

Open

DATE: March 22, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Joe Miller -- Product Support Manager, Load King

TITLE: None

ATTACHMT: Attached to letter dated 12/10/93 from Joe Miller to John Womack

TEXT:

This is in response to your FAX December 10, 1993.

You have informed us that Load King manufactures trailers, selling them to a dealer in Minneapolis who, in turn, sells these trailers to customers/ users. You would like the dealer "to do some finish manufacturing for us." "Specifically, you would like the dealer "to paint the trailers, install operational decals and place the conspicuity striping." You ask whether "primed trailers can be moved without conspicuity striping in this case."

The answer is no. Under the National Traffic and Motor Vehicle Safety Act and its regulations, when a completed motor vehicle is delivered to its dealer, it must be certified as conforming to all applicable Federal motor vehicle safety standards, and it must, in fact, comply with all such standards at the time of delivery. Thus, your trailers are required to be equipped with the conspicuity treatment at the time of shipment since the treatment is a requirement of Motor Vehicle Safety Standard No. 108. The Minneapolis dealer, however, may apply paint and decals since this is not required under Standard No. 108 or any other regulation.

Were the trailer one that is manufactured in more than one stage, our regulations would permit the final stage manufacturer to apply the conspicuity treatment since that manufacturer is required to affix the necessary certification of compliance with all standards upon completion of the final stage of manufacture. However, painting and application of the conspicuity treatment are regarded as minor finishing operations that do not rise to the level of being a separate stage of manufacturing, and this exception is not available under the facts that have been presented to us.

ID: nht95-6.50

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: David Seagren -- Dealer Principal, Pony Express Dodge, Inc.

TITLE: NONE

ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Peter F. Marthy (A43; Part 580)

TEXT: This is in response to your letter sent to this office by telefax on September 12, 1995. In your letter, you ask whether it is permissible to alter an odometer that registers kilometers rather than miles by multiplying the kilometer reading by .62, when there had been a previous attempt to convert the reading to miles. Your letter states that the earlier attempt resulted in the odometer being set back to the equivalent in miles but the odometer continued to register distance in kilometers.

As you are aware from a Federal Register notice faxed to you by Eileen Leahy of this office, the National Highway Traffic Safety Administration (NHTSA), the Federal agency with responsibility for the odometer disclosure regulations promulgated pursuant to the Truth in Mileage Act of 1986 (TIMA) has stated that it is permissible to reset the odometer from kilometers to miles by multiplying the number of kilometers shown on the odometer by .62, and that it is also permissible to certify that number of miles as "actual" when completing the odometer disclosure statement when ownership of the vehicle is transferred.

The rationale for this policy is that "mileage" is defined in the Federal regulations as distance traveled, and it is permissible to express the number either in miles or metrically if it is known that it reflects the actual distance traveled and that the disclosure of the odometer reading specifies which system of measure (miles or kilometers) is being used. Because the conversion from kilometers to miles can be accurately made simply by multiplying the kilometers on the odometer by 0.62, the agency believes that there is little likelihood that permitting odometer readings that have been converted from kilometers to miles to be recorded as "actual mileage" will result in an inaccurate or misleading representation of the distance a vehicle has traveled.

The situation you describe is more complicated because a previous owner of the vehicle in question had already set back the odometer to the mileage equivalent after purchasing it with an odometer reading in kilometers, but according to your letter did not execute properly the procedure necessary to make the odometer register miles rather than kilometers while being driven. The result of this error has been the addition of kilometers to a figure that reflected miles rather than kilometers traveled.

In order to permit recording of a conversion of the present odometer reading from kilometers to mileage as "actual mileage" in this circumstances, two criteria must be satisfied. First, it must be apparent that the calculation at the time of the first conversion was done properly so that it reflects the actual number of miles the vehicle had traveled at that time. From the documents you submitted reflecting the events that occurred prior to your purchase of the vehicle, it appears that the previous owner properly converted kilometers to miles. Accordingly, the first criterion is satisfied.

It is then necessary to establish that the reading now shown on the odometer accurately represents the distance traveled by the vehicle since the first attempted conversion. There is no indication in any of the documentation you furnished that there have been any intervening alterations to the odometer or changes in the way it has recorded distance that would alter the accuracy of its current reading. In addition, you state that since your company has owned the vehicle, the odometer has consistently operated in a way that shows that it was registering kilometers rather than miles. Based on these factors, it appears that it will be possible for you to ascertain with accuracy the distance the vehicle has traveled since the first conversion from kilometers to miles was made.

The proper way to do this conversion is to subtract the number shown as the reading in miles as a result of the calculation made at the time conversion was first attempted, from the number showing on the odometer when you transfer ownership of the vehicle. The result will be the total kilometers the vehicle has traveled since that time. To arrive at the number of miles traveled since the attempted conversion, the result of that subtraction is to be multiplied by 0.62 as described above. In turn, the number resulting from that multiplication is added to the number of miles at the time of the first conversion and the sum is the total number of miles traveled by the vehicle at the time of transfer. You may then properly certify on the odometer disclosure statement when you transfer ownership of the vehicle that that number is its actual mileage.

Because the Kansas Motor Vehicle Department asked that you contact this office for our interpretation of the proper way to handle the sale of this vehicle under the Federal odometer disclosure regulations, it would be advisable to provide that office with a copy of this letter either before or at the time of your application for a new title.

I hope this information is helpful. If you have any further questions about this matter, please contact Eileen Leahy, an attorney in this office, at the address shown above or at (202)366-5263.

(9/12/95 telefax from David Seagren to NHTSA is not available.)

ID: nht74-2.9

Open

DATE: 03/19/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: American Snowblast Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your March 4, 1974, question whether your rotary snowplows, constructed with four-wheel drive and four-wheel steer and a top speed of 35 miles per hour, must be certified to conform to Federal motor vehicle safety standards. You also asked whether "certified brakes" will be sufficient certification to Standard 121, what the effects of a locked transfer case are on an anti-lock system, and what procedure exists to petition for an exemption from the standard.

I have enclosed an information sheet which explains that the vehicles you build for highway use are motor vehicles subject to the standard. The standard applies to the performance of the vehicle as a whole, not just to the brake system. In the event that the vehicles as completed do not actually comply, it is the manufacturer of the vehicle who is responsible.

I have enclosed a copy of the law and regulations explaining the basis for and necessary procedures to apply for a temporary exemption from our safety standards.

With regard to a locked transfer case, S6.1.11 of the air brake standard requires:

S6.1.11 Special drive conditions. A vehicle equipped with an interlocking axle system or a front wheel drive system that is engaged and disengaged by the driver is tested with the system disengaged.

Yours truly,

ATTACH.

March 4, 1974

Department of Transportation - NHTSA

Attention: Sid Williams

Gentlemen:

Please give us your opinion on where we stand with respect to FMVSS-121.

We build large rotary snowplows (brochure enclosed) which are sold primarily to airports. We do build an average of five or so per year for highway plowing, and this is our area of concern.

These machines are air braked, four wheel drive and four wheel steer, have a top speed of 35 m.p.h., and weigh less than 40,000 lbs. but more than 30,000 lbs.

Our questions are: must we certify; will certified brakes be sufficient to certify the vehicle; what are the effects of a locked transfer case on anti-lock; the procedure for petitioning for an exemption, etc.

Sincerely

AMERICAN SNOWBLAST CORPORATION;

D. L. Massy -- Chief Engineer

Enclosure Omitted.

ID: nht80-1.41

Open

DATE: 03/26/80

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: David Williams

TITLE: FMVSR INTERPRETATION

TEXT: I would like to clarify my remarks of March 17, 1980, with respect to the applicability of Federal motor vehicle safety standards to imported vehicles.

In that letter I implied that there was a prohibition against importing cars that didn't meet Federal standards and that such vehicles had to comply with standards in effect on the date of importation. Actually, a nonconforming vehicle may be imported under bond if it will be brought into compliance within 120 days of entry with all applicable standards in effect on the date of its manufacture.

ID: nht91-6.2

Open

DATE: September 18, 1991

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: John E. Calow -- Senior Safety Engineer, Oshkosh Chassis Division

TITLE: None

ATTACHMT: Attached to letter dated 8-12-91 from John E. Calow to Taylor Vincon (OCC 6358)

TEXT:

This responds to your letter of August 12, 1991, to Taylor Vinson of this Office, asking for a verification of your understanding of certain requirements of Motor Vehicle Safety Standard No. 108.

Specifically, you ask:

"If the Brake Lights and Hazard Warning Lights are optically combined and both are activated (per federal regulations) which of the following will occur?

A) The brake lights will over-ride causing a steady light emission.

B) The hazard lights will over-ride causing a flashing light emission.

The answer to your first question is either "A" or "B" depending on how the manufacturer decided to wire the vehicle. The vehicular hazard warning signal operating unit is required to operate sufficient turn signal lamps to meet, as a minimum, the turn signal lamp photometric requirements of the standard (see S5.5.5) and function (see Table I or III) in accordance with SAE J910, January 1966. Since the vehicular hazard warning signal operating unit causes turn signal lamps to operate simultaneously, the turn signal lamps become hazard warning lamps that are optically combined with turn signal lamps. Should these hazard warning lamps also be optically combined with the brake lamps, as in your question, the standard does not provide any requirement for which, brake or hazard, should override.

You also ask:

"If the vehicle has a Center High Mounted Stop Lamp 'CHMSL' is it acceptable to have the Hazard Warning Lights over-ride the Brake Lights if the CHMSL has a steady light emitance (sic) upon brake application?"

The answer to this question is the same as the first. However, the CHMSL may not be combined, optically or otherwise, with any other lamp, and therefore it must remain operative upon brake application, even if the remaining stop lamps have been overridden.

I hope that this answers your questions.

ID: nht95-2.48

Open

TYPE: INTERPRETATION-NHTSA

DATE: April 24, 1995

FROM: Philip R. Recht -- Acting Chief Counsel, NHTSA

TO: Jeffrey D. Shetler -- Manager of Government Relations, Kawasaki Motors Corp. U.S.A.

TITLE: NONE

ATTACHMT: ATTACHED TO 3/29/95 LETTER FROM JEFFREY D. SHETLER TO TAYLOR VINSON (OCC 10826); ALSO ATTACHED TO 2/7/94 LETTER FROM JEFFREY D. SHETLER TO NHTSA ASSOCIATE ADMINISTRATOR FOR ENFORCEMENT; ALSO ATTACHED TO 5/6/94 LETTER FROM JOHN WOMACK TO JEFFREY D. SHETLER

TEXT: Dear Mr. Shetler:

We are responding to your FAX of March 29, 1995, to Taylor Vinson of this Office.

On May 6, 1994, we advised you that a motorcycle headlamp with an upper beam projector on one side of the vertical centerline and a lower beam projector on the other did not comply with Standard No. 108. You now ask whether the headlamp would comply if an exterior housing were installed on the headlamp which "provides the appearance of two headlamps."

This modification in the design does not result in a complying headlamp. Regardless of its exterior appearance, the lamp remains a single headlamp incorporating both an upper and lower beam projector. Since both projectors are within a single headlamp, both projectors must be on the vertical centerline, as specified in Table IV of Standard No. 108.

Even if the upper and lower beam projectors were in separate units, neither in itself would be a complying headlamp, and hence not a two-lamp system that could be mounted symmetrically about the vertical centerline. Standard No. 108 does not permit moto rcycles to have a headlamp system with asymmetrical beam location.

If you have any further questions, you may refer them to Taylor Vinson of this Office. (202-366-5263).

ID: nht89-2.27

Open

TYPE: INTERPRETATION-NHTSA

DATE: JULY 5, 1989

FROM: DAVID G. GOULD -- LEGISLATION DEPT., LOTUS ENGINEERING, NORFOLK, ENGLAND

TO: STEVE WOOD -- OFFICE OF CHIEF COUNSEL, NHTSA

TITLE: WMI REGISTER

ATTACHMT: ATTACHED TO SEPTEMBER 29, 2989 LETTER FROM STEPHEN P. WOOD, NHTSA, TO DAVID G. GOULD, LOTUS ENGINEERING;[REDBOOK A34; PART 565]

TEXT: Lotus Cars Ltd was allocated the WMI "SCC" some years ago by the British Standards Institution - BSI - in England. BSI handles the issuance of WMIs and the maintenance of the United Kingdom WMI register; they notify SAE, the world coordinating body, of those WMIs assigned.

Due to a difficulty that we are experiencing with BSI, Lotus Cars wish to establish the mandate that BSI has with respect to additions to and deletions from the world register, and we have been advised to consult you on this matter.

Specifically, we seek advice on whether a national agency (BSI in the case of the United Kingdom) can delete an allocated WMI from SAE's master register without the agreement of the holder of that WMI, for whatever reason.

Our concerns in this matter stem from the fact that the WMI is a legally required component of the VIN, itself a legal requirement in the European Community, and we would not wish to be deleted from the SAE master register as a result of our difficulties with BSI.

We understand from the SAE WMI co-ordinator in Warrendale PA that WMIs must be allocated by a national body, and cannot be allocated by SAE outside the USA.

We would therefore welcome your views on this query.

Yours sincerely,

ID: nht94-4.23

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 7, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: C. N. Littler -- Motor Coach Industries, Administrator Regulatory Affairs, Winnipeg, Manitoba, CANADA

TITLE: NONE

ATTACHMT: Attached to Letter Dated 01/06/94 from C. N. Litter to Mary Versailles

TEXT: This responds to your letter concerning whether a New York State law addressing the in-use stopping ability of privately owned motor coaches is preempted by Federal law. I apologize for the delay in our response. The New York law states that a vehicle must be capable of stopping "at a rate of deceleration equivalent to a stop within 22.2 feet from a speed of 20 miles per hour." You believe that @ 103(d) of the National Traffic and Motor Vehicle Safety Act ("Safety Act") preempts the New York law, sinc e the state law is not identical to Federal motor vehicle safety standard No. 121, Air Brake Systems. Please note that the Safety Act has been codified at 49 U.S.C. 30101 et seq. and that the citation for 103 (d) is now 49 U.S.C. @ 30103.

As explained below, Standard No. 121 currently does not have stopping distance requirements in effect; therefore, the New York law is not currently preempted by a Federal safety standard. Nevertheless, the agency has issued a proposal to reinstate stopp ing distance requirements in Standard No. 121. (58 FR 11003, February 23, 1993). If the agency issues a final rule to reinstate stopping distances, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted.

Title 49 U.S.C. @ 30103 states:

Whenever a Federal motor vehicle safety standard . . . is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item of motor vehicle equipm ent any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard.

That provision preempts New York's law if there is a Federal safety standard in effect, the state law covers the same aspect of performance as that Federal standard, and the State law is not identical to the Federal safety standard. While you are correct that Standard No. 121 refers to stopping performance in S5.3.1, you apparently were not aware of a provision in S3 that states

Notwithstanding any language to the contrary, sections S5.3.1, S5.3.1.1, S5.3.2, S5.3.2.1, S5.3.2.2, S5.7.1, S5.7.3(a) and S5.7.3(b) of this standard are not applicable to trucks and trailers, and section S5.3.1 of this standard is not applicable to b uses.

The agency amended the standard to include this provision as the result of a ruling in PACCAR v. NHTSA, 573 F.2d 632, (9th Cir. 1978), cert. denied, 439 U.S. 862 (1978), in which a Federal Court of Appeals invalidated Standard No. 121's stopping distance requirements until the agency obtains "more probative and convincing data evidencing the reliability and safety of vehicles that are equipped with antilock." While the provision did not originally cover buses other than school buses, NHTSA extended the provision to non-school buses in 1987. See 52 FR 20602. Because there are no Federal stopping distance requirements in effect, the New York law is not preempted.

As noted above, NHTSA has issued a notice proposing to reinstate stopping distance requirements for air braked vehicles. The agency is currently reviewing comments to that proposal, and may issue a final rule reinstating stopping distance requirements. If the agency decides to amend Standard No. 121 to include such requirements, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted.

I note that the New York law applies to vehicles in use, while Standard No. 121 applies to new vehicles. In general, State laws governing the operation of vehicles are not preempted by inconsistent Federal motor vehicle safety standards unless the State law is more stringent than the Federal standard (with respect to the same aspect of performance). A more stringent law would be preempted, since it would preclude the sale of vehicles that comply with Federal standards.

I also note that the in-use braking performance of many motor coaches is regulated by the Federal Highway Administration. We have referred your letter to that agency's Office of Motor Carrier Standards concerning the issue of whether its regulations pre empt the New York law.

I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. If you wish to contact someone in the Federal Highway Administratio n's Office of Chief Counsel concerning the motor carrier standards, please call Charles Medalen at (202) 366-1354.

Request an Interpretation

You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:

The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590

If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.

Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.

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