BUR #5430 has been approved by @evazion.
create alias lord_of_the_rings -> the_lord_of_the_rings
create implication the_lord_of_the_rings -> legendarium
create implication the_hobbit -> legendarium
create alias silmarillion -> the_silmarillion
create implication the_silmarillion -> legendarium
LOTR's name always has a "the".
As for the name of the umbrella tag, "legendarium" is the common term for the entire body of works of Tolkien. I don't think there's any chance it could be mistaken for another collection of legends. But I guess it could be named "legendarium_(tolkien)" if we really want to be pedantic.