3.2 References:

H 187 When To Establish A New Heading:

"Establish a subject heading for a topic that represents a discrete, identifiable concept when it is first encountered in a work being cataloged, rather than after several works on the topic have been published and cataloged."

H 198 Creating Authority Records For Headings Formerly Unprinted In LCSH (p.2):

"If, in establishing a new heading or in creating an authority record for a heading that previously had none, it is necessary to use, as a broader term in a 5XX field, another heading that lacks an authority record, prepare an authority worksheet also for the heading needed for use as a broader term...Continue upward in the hierarchy in this manner until no additional headings lacking authority records are encountered."