A cover isn't the whole edition
The cover says Revision A. Several pages say Revision B. An MBTA D40LF operator's guide shows why a collector's index needs more than the date on the front.
Follow the revision record
The cover of the SR1105/1106/1121 guide carries Rev. A and the date 04/10/2006. Open the revision index, however, and there is a Revision B entry dated 25/10/2006. It identifies changes to the contents, vehicle specifications, exterior illustration, driver's-area material and other sections.
Those changes are present in the supplied file. The front exterior drawing on PDF page 28, for example, has a Revision B footer. Other pages retain Revision A. Describing this simply as an original Revision A guide would leave out part of its publication history.
For a collection index, record both the original issue and the latest revision actually included. Keep the source's date format when it is ambiguous, and do not substitute the file's creation timestamp for the printed revision record.
Keep the coach groups with the document
The first page lists SR1105 unit 0600 and SR1106 units 0601-0609. The SR1121 list continues on the following pages, ending at unit 0754. A note at the end separates unit 0600, units 0601-0609 and units 0610-0754, explaining that applicable pages identify differences between those groups.
That is useful collecting information. A model name gives you a starting point, while the coach list tells you which vehicles this particular guide describes. Neither the agency name nor the D40LF designation alone makes it interchangeable with another publication.
Make the file easier to find again
A useful entry could read: MBTA D40LF operator's guide; SR1105/1106/1121; listed units 0600-0754; Revision B material included. Keep the PDF page number beside a citation too: the drawing labeled page 16 in print is PDF page 28 because the file includes front matter.
This does not make one edition rarer or more valuable than another. It makes the collection more precise. When you return to a vehicle detail or compare a second copy, you can tell which document you actually have.
Explore the publications
Sources & references
- MBTA D40LF operator guide — identity and initial coach groups, PDF page 1
- D40LF guide — final coach group and applicability note, PDF page 6
- D40LF guide — revision index, PDF page 7
- D40LF guide — contents, PDF page 11
- D40LF guide — vehicle specifications, PDF page 14
- D40LF guide — Figure 5, PDF page 28 (printed 16)