[TUHS] nl section delimiters

[David Arnold]

nl(1) uses the notable character sequences “\:\:\:”, “\:\:”, and “\:” to delimit header, body, and trailer sections within its input. 

I wondered if anyone was able to shed light on the reason those were adopted as the defaults?

I would have expected perhaps something compatible with *roff (like, .\” something). 

FreeBSD claims nl first appeared in System III (although it previously claimed SVR2), but I haven’t dug into the implementation any further. 

Thanks in advance,



d