A transform block consists of lines, where every 2 lines is a transform The first line of each transform is a pattern, and the second is the replacement. These are passed to re.sub, like so: re.sub(pattern, replacement, page_data)

Here is the set of transforms for the tbwiki.header page:

Ignore the trailbar

transforms
class=trailbar.*
class=trailbar></td></tr>