Generally, when source files are FrameMaker or Interleaf the process is to prepare them with a CAT tool and then start the translation.
The prepared .rtf document looks like this:
<ps "Heading1" 1><pn "Appendix M" 1><:crmk 1>
<ps "Body" 2><:cs "Bold" 1>A<:/cs>: Amperio
Which is kind of nasty but as translators we have to know the following:
a) Grey color indicates external tags and they will never appear within a segment
b) Red color indicates internal tags and we have to be carefull and keep them intact
c) Black color is what has to be translated.
Note that each color correspond to a font style and it has to be kept.