SCM_WRITE_CASE_FOLD 1587 src/gauche.h       SCM_WRITE_CASE_FOLD = 4,    /* case-fold mode.  need to escape capital
SCM_WRITE_CASE_FOLD  132 src/symbol.c               ((SCM_WRITE_CASE(ctx) == SCM_WRITE_CASE_FOLD)? 0x12 : 0x02);
SCM_WRITE_CASE_FOLD  115 src/write.c        SCM_WRITE_CASE_FOLD:SCM_WRITE_CASE_NOFOLD)