1.6 Constants
libpeios does not invent its own names for the kernel's wire constants. The access-right bits, ACE types, control flags, and mapping structs all come straight from the <pkm/*.h> UAPI headers, and you use those published names directly: KACS_ACCESS_*, KACS_ACE_TYPE_*, KACS_SD_*, struct kacs_generic_mapping, and so on. There is no parallel PEIOS_* aliasing to translate in your head — the name in the PSD, the name in the kernel header, and the name you write in your code are the same name.
The handful of constants that are libpeios's own — buffer-size ceilings like PEIOS_SID_MAX_BYTES, and enums for convenience selectors like enum peios_wks (well-known SIDs) — are prefixed PEIOS_ and documented with the module that defines them.