Just a small correction to the documentation that would have saved me some time if I'd noticed it sooner:
createFileAsset has this explanation for link type:
Type of link to create for File asset (SQ_LINK_TYPE_1, SQ_LINK_TYPE_2, SQ_LINK_TYPE_3, or SQ_LINK_NOTICE)
Value of the link to create to parent for this new asset
Custom callback function whereas all the link functions (and getparents/children) have this:
Type of link we are looking for: SQ_LINK_TYPE_1, 2, 3 or NOTICE
I'm not sure how anyone would arrive at "SQ_LINK_NOTICE" from the latter, if you could update them all to be like the createFileAsset one then you might save someone else some frustration :)