They only hold links. The integration daemon we run synchronises the fields so that the fields link to the SharePoint item.

A couple of approaches spring to mind, then:

1. We can let the Remarkup control have an 'inline' flag which renders it inline instead of in a block at the bottom; this will highlight the link as a side effect.
2. We can write a "link" control which accepts a link. I think this is pretty reasonable to put in the upstream.
3. You can also define your own "link" control externally now -- basically copy PhabricatorStandardCustomFieldText and dump it somewhere where it will load at runtime.

Any preferences here? (1) or (2) both seem reasonable to me, maybe with a slightly preference for (2). It sounds like they'd both fit the bill, but if you need more magic than those, maybe (3)?

With (1), you could sync some text like:

[[ http://sharepoint.whatever/29382389 | Sharepoint #29382389 ]]

...to get a prettier link, I suppose.

(2) sounds good to me. I don't like the idea of (1) because it would permit any form of Remarkup, and in this case we explicitly want to store a link in that field.

FWIW It would be cool to have a list of links. We use a free text field for support cases (many external tickets:one internal ticket) which mostly working but sometimes people type random junk in the next block to celebrate their freedom.

people type random junk in the next block to celebrate their freedom

This company fully supports the jubilant celebration of human freedom.