Causes the system linker to search the specified library for any external routines. The -l cob flag is effectively the same as the -l option for the system linker, ld (see your operating system documentation for further details on this linker option). The order in which -l options are specified is significant as libraries are searched in that order.
A library is searched when its name is encountered, so the placement of the -l flag is significant. See -L for more details.