MoinMoin processing instructions have the same semantics as in XML: they control the paths taken when processing a page. Processing instructions are lines that start with a “#” character followed by a keyword and optionally some arguments. Two consecutive hash marks at the start of a line are a comment that won't appear in the processed page.

Processing instructions this wiki knows of:

• ## any-text: comment
• #FORMAT format-specifier: defines the input format for this page, known formats are:
• 'Wiki': default MoinMoin wiki markup
• 'Plain': normal plain text
• 'Python': colorized Python source
• 'HTML' ( <!> not implemented)
• 'StructuredText' ( <!> not implemented)
• #REDIRECT pagename: redirect to a different page (see MeatBall:PageRedirect'')

All PIs must appear at the very start of a page. An exception are comment PIs, those may appear within a wiki page (but obviously not in pages using other formats).

For more information on the possible markup, see HelpOnEditing.