If the ‘@%’ command (see AT%) is used to comment out a line, it eats the trailing newline. An undesirable consequence of this is that, if nothing is done, the subsequent line numbering will be misunderstood by a debugger, at least until FWEB inserts a ‘#line’ command for some reason. To prevent this, FWEB inserts by default an implicit ‘@#line’ command (see Preprocessing) after each ‘@%’ that begins a line. To prevent this from happening (possibly because the feature doesn’t work correctly, in which case you should report it; see Support), use the ‘-T#’ option.