CEL looks interesting and useful, though it isn't common nor familiar imo (not for me at least). Quoting from https://github.com/google/cel-spec

    # Common Expression Language

    The Common Expression Language (CEL) implements common
    semantics for expression evaluation, enabling different
    applications to more easily interoperate.

    ## Key Applications

    - Security policy: organizations have complex infrastructure
      and need common tooling to reason about the system as a whole
    - Protocols: expressions are a useful data type and require
      interoperability across programming languages and platforms.