Describes the usage of libraries within the processing and generation of information files. The data contained within covers both the definition and usage of internal (existing within the information file) and external libraries. The libraries can be used to make generated data more compact and facilitate data exchange and archival. The subroutines within a library can be used one or more times within any Data Information Module and also in one or more Data Modules. Supplements the IPC-D-350 series. This document does not cover specifics of other standards in the series. This document is frozen; no future updates are planned. 39 pages. Released February 1987.