CS-STACK CS-ROLL CSET
CS-STACK the Computational Stack (-Pointer)  
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is implicitly accessed by many immediate compiling words, especially with IF THEN ELSE BEGIN REPEAT and other control words, and also by LITERAL and SLITERAL since the CS-STACK is actually the same as the normal Parameter Stack Pointer SP in PFE. As with the Forth Standards, the CS-STACK could be a seperate stack which is very useful with a Forth Assembler. Since PFE is fully written in C and intends to be fully portable, there is hence no such need.

reference: CS_minus_STACK in doc-pfe.cdoc:0058, export never CS-STACK