The Government Printing Office or GPO defines a document as not only print or microfiche but also any informational matter produced for public dissemination, in any format. Unfortunately, GPO's liberal definition of pre-electronic legal language is not always shared by government issuing agencies. Some agencies neglect to supply GPO with depository copies of their information products, either paper or electronic. So, despite the best efforts of GPO and libraries, not all documents which belong in the depository system get distributed in it. St. Mary's Academic Library is a depository library as is the St. Mary's Law Library.
Depository libraries receive federal government documents for free.
The libraries, in exchange for the free information, promise to organize and care for the documents and make them available to the public. Most depository libraries are selective depositories. This mean that the library has a choice of what material to receive and how much material to receive. The public library receives the largest amount of depository material in San Antonio. There are also regional depository libraries in other cities that receive and retain permanently all depository material.