Question

Answer

MyCoordSysDefs.fme is a file that holds custom coordinate systems when they are defined by the user.

Users provide their own local definitions in the MyCoordSysDefs.fme file which can either override, or more likely, supplement the definitions that FME ships with. In addition, users can use an FME Shared Resource Directory to create coordinate system definitions that their whole organization can share.

The structure of MyCoordSysDefs.fme is the same as the override coordinate system file LocalCoordSysDefs.fme, whose contents new custom coordinate systems can use as a template.

NB: It is recommended that users put custom coordinate systems in MyCoordSysDefs.fme, rather than LocalCoordSysDefs.fme, because the latter is overwritten each time a new version of FME is installed.