It seems as though any keyword message, sent to a WATagBrush is going to set an attribute

I have been looking at the various table tags a bit more, and I realised that all of the methods such as scope:, colspace: etc, are implemented as something like

self attributes at: 'summary' put: aString

This is useful for reading the code. With: contains the code that will go between tags and everything else is likely to set the tags attributes.