IR-able injuries?

[aston217]

What injuries are IR-able, and what aren't? Is there a guide to this somewhere?

Just for reference. Sometimes players don't have to be 'out' to be IR-able, for instance.

Was also wondering if there's a list of injuries that cause a player to be unrelease-able.

[Firefly]

Unreleasable is easy: any injured players with multi-year contracts

[imdashep]

Any injury where they are questionable I believe I've been able to IR. May just be a correlation though