Claude tends to work well with such semi-xml tags in practice (probably trained for it?). You can just make them up, and ask it to respond with specific tags,

Claude tends to work well with such semi-xml tags in practice (probably trained for it?). You can just make them up, and ask it to respond with specific tags, too. Like “Please respond with the name in <name>…</name> tags and the <surname>.” It’s one of the approaches to forcing structured responses, or making it role-play multiple actors in one response (having each role in its tags), or asking it to do a round of self-critique in <critique> tags before the final response, etc.