We have a set of documents models that contain inline redaction help  (for
example: list there foo elements if you are in bar situation). Document
structure is too loose to make them forms. 

To help the redaction helps stand out they have a particular styling (specific
font, italic, etc). This styling includes inserting a specific symbol before
each text run. Unfortunately automated character styling does not permit
specifying insertion of this symbol, so it has to be done manually, which is
time consuming, results in inconsistent choices, makes document restyling
difficult, etc Our redaction help texts occur most often in the middle of
paragraphs: they can not be styled using § styles. In HTML they'd be an inline
element

OO.o is proud of its styling ability - they should be extended to cover this
kind of situation.