Thomas Mann’s article on the importance of subject headings inadvertently raises a point that was brought up during our class discussion last week that I think is relevant to our readings. In class we came to the topic of how and why the Library of Congress takes so long to revise its subject heading. Jenna Freedman suggested that the process is prolonged for unavoidable bureaucratic reasons but that another key factor is that the LC catalogers often defend the headings’ inelasticity because they are, after all, describing the LC collection. I agree with Mann that subject heading assignment is still worthwhile because of its value for resource discovery and because there is no computer system sophisticated enough to determine aboutness with any nuance (yet). However, he uses the LCSH’s intrinsic OPAC function for the LC collection as a defense of its implementation. That same function could be construed as a limitation and used as an argument in favor of reallocating resources towards postcoordinate, faceted searching systems. LCSH is widely used because of its exhaustiveness, but there may always be some gaps in its subject relationships as it is mapped onto collections with a unique extent. Interoperability projects for linking resources between local systems could in some near future yield retrieval results that fill in some of these gaps.