And BCPL means Bootstraping CPL, it was never intended to anything beyond bootstraping the CPL compiler that never came to be, as the project folded.
> BCPL has been rumored to have originally stood for "Bootstrap Cambridge Programming Language", but CPL was never created since development stopped at BCPL, and the acronym was later reinterpreted for the BCPL book.
The descriptions of how the CPL compiler worked (eg Strachey’s paper on GPM, Richards more recent retrospectives) all talk about writing the compiler in CPL and translating it by hand to macro assembly.
I have not yet managed to look at Richards PhD thesis which contains the first draft description of BCPL, which he sketched after working on the CPL compiler and shortly before moving to MIT where he first implemented BCPL.