Neither these abbreviations nor their base phrases occurs anywhere in the 
ANSI Smalltalk Standard. The closest similar things would be the chapter 
titles for various groups of related protocols.  Those are:

         Fundamental Protocols
         Valuable Protocols
         Exception Protocols
         Numeric Protocols
         Collection Protocols
         Date and Time Protocols
         Stream Protocols
         File Stream Protocols

Allen_Wirfs-Brock at Instantiations.com

  At 10:40 PM 1/29/2003 +0100, Boris Gaertner wrote:
>CLDT stands for 'Common Language Data Types'
>In IBM Smalltalk there are other abbreviations of that kind:
>
>CLIM  Common Language Implementation
>CPM   Common Process Model
>CFS    Common File System
>CG      Common Graphics Subsystem
>CW     Common Widget Subsystems
>CP      Common Printing Subsystem
>EW     Extended Widget Subsystem
>
>
>I think CLDT, CLIM, CPM are taken form the ANSI standard.