standard specifies that they return \fBERR\fR on failure, but specifies no
error conditions.
.PP
Some historic curses implementations had, as an undocumented feature, the
ability to do the equivalent of \fBclearok(..., 1)\fR by saying
standard specifies that they return \fBERR\fR on failure, but specifies no
error conditions.
.PP
Some historic curses implementations had, as an undocumented feature, the
ability to do the equivalent of \fBclearok(..., 1)\fR by saying