I’m not able to reproduce this effect - merely by adding such text to the body of an RTFD and then importing it:
Is it possible that whatever process is creating the RTFDs is also adding the keyword metadata to the file(s)? Where these files originally produced by an export process involving HTML that incorporated </> tags?
Except in the case of HTML that includes such “meta” tags, DT does not parse imported text looking for keywords, tags or any other metadata. For imported documents, if there exists OpenMeta extended attributes containing tag values, then DT will recognize the tags and create DT Tags associated with that document. This is really the only way that imported documents get Tags associated with them.
The whole topic of keywords, metadata, and tags is often confusing. Perhaps this post might help sort it for you.