I'm not entirely sure what you mean by "permalink" but I'm guessing that this is some kind of URI indicating whereabouts a facsimile of a manuscript is to be found. But in that case it's strictly speaking not part of the msIdentifier at all, since this is all about identifying the *manuscript* itself, not facsimile images of it.

I'd put such information in the <surrogates> element

On 25/06/14 08:32, Marcel Illetschko wrote:
[log in to unmask]" type="cite"> Hi all!

The guidelines say that <altIdentifier> could "contain an alternative or former structured identifier used for a manuscript, such as a former catalogue number."
All the examples and explanations only cover former identifiers, usually in a different holding institution. I would like to use <altIdentifier>-elements to show that a manuscript lies at department A of institution B and has the permalink C.
Do you think that's okay?

Thank you for suggestions,