Any provision for rulers in ScanTailor?

[Marc de Piolenc]

In the reprinting work that I do, I need to fit the "select content" into a page so that it is positioned naturally, but leaves all the content out of the non-printable areas. This means manually setting margins, because of extreme variability in the content. But I need an on-screen guide to show me when my margins are correct, but not excessive. There does not seem to be a "show ruler" feature in ScanTailer as there is in Acrobat for example. At least, I can't find it.