[groff] anyone seen ".ny0" ?

[Walter Harms]

Hello list,
while looking at the xorg man pages there came
a question what this  .ny0 may mean (i shorted that of cause):

....

.ny0
.TH XtAppNextEvent __libmansuffix__ __xorgversion__ "XT FUNCTIONS"
.SH NAME

.....

I could not find this in the groff manual. It seems to do nothing.
Any ideas ?

re,
 wh