The concept is similar to formula, but it allows to create named variables - instead of strict numeric sequences. There are two use cases (reflected on column names):
A: you already provide your marked-up text B: you set a plain text and let the parser identify the replaceable words
You can decide what kind of markup you prefer (and even create your own!).
It also support case-sensitiveness.
Disclaimer:
Please, note that the the substitution relies on RegexExtract() formula which is not currently supported (hopefully, it will be), therefore is strongly discouraged to use this in critical contexts, as it might be discontinued.
Also, this is a playground document, subject to changes and incomplete.
To be addressed: non alphanumeric chars in - or adjacent - variables for plain text (see column B.2)