Should we use seeAlso or create a predicate for LoCFDD or Wikidata?

[ross-spencer]

I will hedge my bets and use seeAlso for both, but there seems to be a pattern out there of having specific properties. This has the benefit of being easy to find, but is yet another property. As a developer or user of the service I might only want a property if I also wanted to describe the resource type, e.g. what the LoC service offers and what users should consider when looking up those links.