[JJR512]

Yes, those hacks do exist. They don't have to exist plentifully; all you need is one, that modified just one line that another later hack also wants to modify. One such very extensive hack is ethank's persistent mark forum read hack.

And yes, you can search for just a part of the line. The potential problem with that is that as you make your search less specific, the chances increase of you finding what you're searching for more than once. In that event, you can either look at the text around each hit, and see if it looks close enough to what you're supposed to be looking for that you can reasonably decide you've found it. Alternatively, line numbers would make that process a lot easier; you would just have to find the partial search terms at or near the specified line number.

Please understand, I am not saying that line numbers are the ultimate best solution. There are multiple ways for handling any situation here, and what might be best for you, might not be best for some (anybody feel like singing the theme song from Diff'rent Strokes? ).