I'm pretty sure you don't release pre-release versions without -pre or -beta or ...

dan15 · on Feb 22, 2018

Technically you don't have to with semver, it's just a good practice. From https://semver.org/:

> A pre-release version MAY be denoted by appending a hyphen and a series of dot separated identifiers immediately following the patch version.

Note that it says "MAY" and not "MUST", so it's optional.