In looking at tcl 8.6a2, I noticed today that a few tcl man pages are not being handled as expected by Sun's man command.
$ man -s n lreverse
Reformatting page. Please Wait...unknown preprocessor specifier -
The issue is that the first line of this man page happens to be
'\" -*- nroff -*-
This causes Sun's man command to attempt to invoke the text as an nroff preprocessor.
In the past, people have moved those lines to the bottom of the file, I think, to keep the indicator and not trigger the man command error.
Right now, I have seen the problem in man pages such as lreverse, mathop, regexp, regsub, and a number of tk man pages.