conv_dl_flag
fmt = conv_dl_flag(head->ch_dlflags, 0, &dl_flag_buf);
conv_dl_flag(head->ch_dlflags, CONV_FMT_ALT_CRLE,
extern const char *conv_dl_flag(int, Conv_fmt_flags_t,
conv_dl_flag(flags, 0, &dl_flag_buf));