Mostly we see reserved mappings for
- drive for main applications.
- drives for special applications f.e. old DOS applications.
- home drive.
- drive of your main department.
- drives for sub departments. mostly necessary for people with more functions.
- drive for temporary files. mostly useful for temporary storage and
fast sharing data.
The possible problem with reserved letters for old DOS applications can
be solved by using a BAT file. This BAT we remap a drive before starting
DOS application.
Also it isn't - in our opinion for 'simple' end-users - necessary to have
knoweldge which drives are mapped. We create related shortcuts on the
desktop and in some cases we prevent the possibility to search through
available drives (drives are hidden for explorer).

A more complex problem for OLD software can be the usage of network
printers and printer types.
greetings.