https://community.graphisoft.com/t5/Libraries-objects/IFC-entities-and-subtypes/m-p/104640#M28291 Hi Laura<BR /> <BR /> Sorry it took you so long to receive an answer.<BR /> <BR /> GDL Library Parts are govern by an inertial serial number "GUID" that is composed of 2 parts, the first part tells ArchiCAD what GDL subtype should it reference the new Library Part. <BR /> <BR /> In simple english words for GDL novice: When ArchiCAD reads the object serial number, it will know what type of object it is (ex: door, window, furniture, etc), for more info read GDL guides and manuals<BR /> <BR /> In your case, I guess you have created a new subtype from one that was already available with ArchiCAD, if that was true, then the new subtype that you have created will have a new GUID, but that GUID will reference it parent object, therefore nothing bad will happen. Wed, 15 Jan 2020 17:08:39 GMT Nader Belal 2020-01-15T17:08:39Z https://community.graphisoft.com/t5/Libraries-objects/IFC-entities-and-subtypes/m-p/104639#M28290 <DIV class="actalk-migrated-content"><T>I realize that GDL Object Subtypes are based on IFC entities. Because the "Furnishing" Subtype is hardwired into AC, I've created a copy ("Furnishing_OSL") so I can customize the listing parameters.<BR /> <BR /> Does anyone know if changing the name of a Subtype will affect the IFC functionality?</T></DIV> Thu, 29 May 2008 18:09:24 GMT https://community.graphisoft.com/t5/Libraries-objects/IFC-entities-and-subtypes/m-p/104639#M28290 Laura Yanoviak 2008-05-29T18:09:24Z https://community.graphisoft.com/t5/Libraries-objects/IFC-entities-and-subtypes/m-p/104640#M28291 Hi Laura<BR /> <BR /> Sorry it took you so long to receive an answer.<BR /> <BR /> GDL Library Parts are govern by an inertial serial number "GUID" that is composed of 2 parts, the first part tells ArchiCAD what GDL subtype should it reference the new Library Part. <BR /> <BR /> In simple english words for GDL novice: When ArchiCAD reads the object serial number, it will know what type of object it is (ex: door, window, furniture, etc), for more info read GDL guides and manuals<BR /> <BR /> In your case, I guess you have created a new subtype from one that was already available with ArchiCAD, if that was true, then the new subtype that you have created will have a new GUID, but that GUID will reference it parent object, therefore nothing bad will happen. Wed, 15 Jan 2020 17:08:39 GMT https://community.graphisoft.com/t5/Libraries-objects/IFC-entities-and-subtypes/m-p/104640#M28291 Nader Belal 2020-01-15T17:08:39Z