Originally posted by @ArthurSens in #15258 (comment)

Due to historical reasons, the translator code was copied from OpenTelemetry collector codebase.
Over there, they tried to provide means to translate metric names following Prometheus conventions that are documented here.

Although not explicitly said, it was implied that words should be separated by a single underscore and the codebase was written with that in mind.

Now that we're allowing OTel users to have their original names stored in prometheus without any transformation, we're facing problems where two (or more) UTF-8 characters are being used to separate words.

A few examples:

• http______requests_total becomes http_requests_total
• http...._requests....total becomes http.requests.total

In summary, we want to fix the bug documented in code here