Any idea what metalogic is for?

If we look at arjafi's query data.stackexchange.com/math/query/542457/… it was probably created by Doug Spoonwood in Does There Exist A Fourth Independent Axiom Here?

Although the tag exists for a long time, which makes the query less reliable. But I have not found deleted posts with that tag older than 2014: data.stackexchange.com/math/query/858309/…

It would be nice if tag-creators also created some basic tag-wiki - at least to make clear what they intended the tag for.

WP: Metalogic:

> Metalogic is the study of the metatheory of logic. Whereas logic studies how logical systems can be used to construct valid and sound arguments, metalogic studies the properties of logical systems. Logic concerns the truths that may be derived using a logical system; metalogic concerns the truths that may be derived about the languages and systems that are used to express truths.

> The basic objects of metalogical study are formal languages, formal systems, and their interpretations. The study of interpretation of formal systems is the branch of mathematical logic that is known as model theory, and the study of deductive systems is the branch that is known as proof theory.

I am not sure - the above is probably already covered by logic, model-theory and proof-theory.

It would be nice to hear from the people active in the logic tag and related tags.

@AsafKaragila Do you plan to make a post on meta about this?