Rich Text and the <tag:open:close> tag using multiple characters

The documentation states that you can use multiple character for the <tag> open/close characters. This is not what I am finding. Using anything more than single characters for the open/close tag characters does not work.

This shows multiple characters used for the new tag characters:


This is for single new tag characters:


Both formulas are the same except for the number of <tag> characters used. I also noticed that the documentation example for the <tag> uses a comma separating the open and close tag characters when it should be a colon.