S Page, 03/01/2014 03:11:
[...] This happens because the 'flow-topic-participants' message goes through parse(), and in wikitext a leading blank formats the text as a <pre> tag. [...] 2) Is there an idiom to guard against this unintended <pre> tag generation, without making the message[1] even more complicated? E.g. we could put some zero-width Unicode character at the start.
You should not have a leading space. If for some reason you need to assemble various things and the space needs to be in the message, you'll need to use the HTML entity for it.
Nemo