1. This function returns a property of an external type (types provided by modules or user defined). For the property XPRM_TPROP_NAME, the type name is returned in value->string, for the 3 other properties, the result is returned in value->integer.

2. The type features are bit encoded as follows:

XPRM_MTP_CREAT	Creation function available for this type
XPRM_MTP_DELET	Deletion function available for this type
XPRM_MTP_TOSTR	Type can be converted to a string
XPRM_MTP_FRSTR	Type can be initialized from a string
XPRM_MTP_PRTBL	Type can be converted to a string after execution
XPRM_MTP_RFCNT	Type implements reference count
XPRM_MTP_COPY	Type implements copy: it may be used in assignments
XPRM_MTP_APPND	The copy function of this type supports appending
XPRM_MTP_ORSET	The copy function of this type can only be used to reset an object
XPRM_MTP_PROB	Type is a problem
XPRM_MTP_CMP	Test of equality is supported by this type
XPRM_MTP_SHARE	An entity of this type can be declared as shared
XPRM_MTP_TFBIN	Type supports export/import in binary format
XPRM_MTP_ORD	Type supports comparison
XPRM_MTP_CONST	Type supports constant definition

3. The expanded type is available for user defined types only: it corresponds to the actual type (including structure information) associated to a user defined type code. For instance, assuming the type myset is defined as a set of integer, getting the type expansion for the code associated to myset will give XPRM_STR_SET|XPRM_TYP_INT indicating that a reference to an entity of type myset has to be handled with functions for sets.

4. Trying to get the expanded type of a module type or the features of a user defined type is an error: the function returns 1. This can be used to identify module types.

5. A user type which expanded value is XPRM_STR_REC is a record type. The public fields of a record type may be enumerated with getnextfield.

6. A user type which expanded value is XPRM_STR_PROB is a problem type. The components of a problem type may be enumerated with getnextpbcomp. Note that problem types are also implemented as native types. In this case, the flag XPRM_MTP_PROB will be set in the type features.

7. If a type refers to a native or record constant the expanded type has structure XPRM_STR_CSREF. The function csrtoref might be used to retrieve the actual object associated to a constant. The property XPRM_TPROP_ITYPS is an array of integers describing the types of the fields of a constant record (it is NULL if the referenced type is not a record). The first cell of this array is the number of fields and each following entry is the type of the corresponding field (this information is required when implementing an IO driver supporting initialisations blocks).