Hi,

I'm trying to customize a cite format in a bibliography. Currently, I'm using the aps style which fits so far, except of the plain number as reference.
In concrete, I want to change the following:
- Use the first letter of the last name and the year as reference (this should be exactly the short form). It is more less also described here [1].
- Highlight publications of a certain author with an extra char (e.g. '>')

Here is a minimal example (lets assume, every occurrence of Knuth should be highlighted):
```
\setupinteraction[state=start]

\startbuffer[testdata]
@Book{knuth1,
	author = {Donald E. Knuth},
	title = {TEX and METAFONT. New directions in typesetting},
	year = {1979},
	publisher = {Addison-Wesley},
}
@Article{someother,
	author = {Some Person and Some Otherperson},
	title = {Another title},
	year = {1900},
}
\stopbuffer

% enable tracing
\enabletrackers[publications, publications.crossref, publications.details, publications.cite, publications.strings]

\usebtxdataset[main][testdata.buffer]
\usebtxdefinitions[aps]
\setupbtx[dataset=main]
\definebtxrendering[bibrendering][aps][dataset=main]

% this seems to have no effect?
\setupbtx[alternative=short]

\starttext

Knuth developed \TeX \cite[knuth1].
Several persons said something \cite[someother].

\placelistofpublications[bibrendering]

\stoptext
```

It should be rendered as:
```
Knuth developed TeX [>Knu79].
Several persons said something [PO00].

[Knu79]	D.E. Knuth, TEX and METAFONT. New directions in typesetting (Addi­son-Wesley, 1979).
[PO00]	S. Person and S. Otherperson, Another title, (1900).
```

How can I achieve that \cite[something] always renders in the short form by default?
How can I customize that references to Knuth contain this extra '>'?
How can I customize the APS style to also use the short form in the list of publications instead of numbers?

Best
Gerion

[1] https://tex.stackexchange.com/questions/295444/citation-style-with-first-letters-of-authors-lastname