well the reason "e1_" is part of that's attribute's name is to control where the option appears in the component options window. with the exception of the predefined size attributes (LenX, LenY, & LenZ, which always appear at the top of the component options window), all other attributes, predefined or custom, get ordered alphabetically in the component options window. if i didn't care where the "back type" option showed up on the list of component options, i'd do away w/ the "e1_" prefix in the name.
but this still doesn't explain why my B2D's "e1_back_type" attribute name is changing to "back_type" upon importation after having imported another cabinet that actually has an attribute named "back_type"...i mean it does and it doesn't. obviously there's a link here, but it doesn't make any sense to me, and i feel like its happening in error.
likewise, the opposite is true - if i were to import the B2D first, i could open the component attribute window and see for myself that there is in fact an attribute named "e1_back_type"...and if i subsequently import a B1D (or any other cabinet with an attribute named "back_type"), all the instances of "back_type" in its formulas will change to "e1_back_type."