What are the correct ways to express parenthetical comments?

Solution 1:

I would always add a comment mid-sentence, unless of course the context called for it at the end anyway.

If I were to add a comment at the end then my British English education compels me to include anything that pertains to a sentence before the full stop (period), not after which I believe is the US English norm?

If one were to add comments at the end of the sentence, how would multiple comments be handled?

The condition was diagnosed during triage by Miss Daniels (a nurse) after she discussed the symptoms with Dr Hanson (a visiting GP).

Solution 2:

I don't know a specific rule for this, but my usage for it is that a parenthetical comment in the sentence itself (like this one) comments on a specific aspect of something in the sentence. A parenthetical comment following the complete sentence is a comment concerning the sentence in general. (I hope that this is clear.)

The example here has the first parenthetical phrase commenting on parenthetical comments in a sentence; the second one actually makes a comment about the whole paragraph. To put it another way, the scoping of the inline comment is "something immediately proceeding me in this sentence", while the out-of-line comment is scoped to "the content of preceeding sentence or sentences".