Standard form for author name in header

[lb42]

Current encoding recommendations say we should encode the author name in a standardised way when it appears in the <author> element inside the <titleStmt>. The recommended format is "Surname, Forenames (birthdate-deathdate). This works for the majority but there are at least three sizeable minority cases where it doesn't.
case 1: birth or death year (or both) are unknown
case 2: the name needs some qualification, e.g. as a pseudonym, or is followed by an alternative name, in either case given in parentheses.
case 3: the traditional way of referring to a person does not have a comma (e.g. Hungarian), or the author is usually identified by a single word (e.g. "Colette")
My suggestions for handling these are:
case 1: give a single question mark for a missing date
case 2: use square brackets rather than parentheses
case 3: i have no satisfactory suggestion

[CarolinOdebrecht]

case3: to be consistent, it would help much if we could use comma even it is not the common way in some contexts. If we do not have to consider much variety it would be easier for parsing the names and for users a like.
When there is no fullname, we could ideally give a parser the chance to detect this, e.g.
-, Colette (1873-1954)
By the way, Colette is (according to viaf) Sidonie Gabrielle Claudine.

[lb42]

So you could do this:

<author>Sidonie, Gabrielle Claudine [Colette] (1873-1954)

or this

<author>Colette [Sidonie, Gabrielle Claudine] (1873-1954)

FWIW, current practice in the French collection shows this:

Gyp [Mirabeau, Sibylle Riquetti de] (1849-1932)

and in the English one:

Ouida, [pseud.] (1839-1908)

I think the main point is that the first word (up to a comma or square bracket) should be the name under which you'd expect to find this author listed. Any variant name, or qualification of the name, should be enclosed in square brackets.