From MorphOS Library
AddDataTypes - Activates datatypes or adds another datatype
FILES/M, QUIET/S, REFRESH/S
FILES - names of the data type descriptors to add to the existing list. QUIET - suppresses error and output messages. REFRESH - scans the DEVS:DataTypes dir for new or changed data type descriptors.
Data type descriptors are stored in DEVS:DataTypes. These descriptors allow programs such as MultiView to interpret different data file types. AddDataTypes can also be called by application installation scripts to add their own data types to the list.