The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM.
For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header.
Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM.
The way we want to use the INITBSS segment - and especially the fact that it won't have the type bss on all ROM based targets - means that the name INITBSS is misleading. After all INIT is the best name from my perspective as it serves several purposes and therefore needs a rather generic name.
Unfortunately this means that the current INIT segment needs to be renamed too. Looking for a short (ideally 4 letter) name I came up with ONCE as it contains all code (and data) accessed only once during initialization.
Moving __cwd from BSS into INITBSS does of course ;-) not only impact the CBM targets but all targets with disk I/O support.
Note: Code using `__cwd-1` may trigger an ld65 range error because __cwd may end up at the very begining of a segment. As far as I see this is an ld65 bug which I'm not try to fix - at least here.