Mebbe TMI, but there's also a tendency to hang onto older designations. "Iron" and not "steel" for "track" might be one example. The new auto yard at the west end of the "Branch" is still frequently referred to as "San-Vel," the older designation of Lone Star, the concrete operation that experienced QA problems with Amtrak ties, went idle, and got eventually repurposed. Not much further west and by West Wye is the Camp track, a name that goes back to WW I and "Camp" Devens, the track's "Camp" designation being held onto during WW II and later after Devens had been upgraded to "Fort" status, retained after Devens was deactivated, and further reinforced by the recent track and signal work at Ayer resulting in CPF-Camp.
As newpylong posted some years ago, during the strike era, there were wholesale mileage-based changes in designations to make things less confusing for the "replacements," but "Wachusett" and "Westminster" -- even before the T Extension -- were used as much as "333" or "335," and a few hours of listening will show that Parkers, Wrights, Tyters, and the other pre-Guilford interlocking names are in general non-Form D and non-241 use.
(The above use of "replacements" is my attempt to remain "civil" to those who fed their families at the expense of others' families.)
"A gray crossover is definitely not company transportation."