The scenario numbering (e.g., LFA101, LFA102, etc.) is difficult to ascertain authoritatively, particularly in the first portion of the series. Many scenarios did not have the numbering embedded in the document and "official" enumerations are rare, fragmentary, and occasionally conflict with each other.
The numbering scheme used here is typical and traditional, though it conflicts in some points with "typical and traditional" schemes used on some other sites. I'm not claiming the one used here is the best or the most-correct - just that it's the one used here.
Probably, it is best to refer to scenarios - especially those early in the series (LFA1nn) - by title rather than enumeration.