api - HAL+JSON representation for links with the same rel -

the hal specification says:

note: if you're unsure whether link should singular, assume multiple. if pick singular , find need change it, need create new link relation or face breaking existing clients.

does making link particular rel singular or multiple apply use of rel within particular resource-representation, or apply use of rel in any resource-representation?

for example, if have decided links under item rel should multiple inside resource x, constraint hold resource x, or hold resource y if happen use item there well?

link relation types defined independently resource representations. in fact regularly defined independently media type can used across media types.

also aware link relation 'item' has been defined , standardized see http://www.iana.org/assignments/link-relations/link-relations.xhtml