The two converters that write tt(groff) output are the tt(man) and tt(ms) 
converters. 

In respect to the output, the following applies. You can start lines with a 
single dot, since all dots are converted by the active character conversion 
table to tt(\&.). However that also means that you cannot easily paste
tt(groff) commands into an output file. If you want to send commands, use the 
macro tt(roffcmd()). 

