This option specifies how keyword completion ins-completion works when CTRL-P or CTRL-N are used. It is also used for whole-line completion i_CTRL-X_CTRL-L. It indicates the type of completion and the places to scan. It is a comma-separated list of flags: . scan the current buffer ('wrapscan' is ignored) w scan buffers from other windows b scan other loaded buffers that are in the buffer list u scan the unloaded buffers that are in the buffer list U scan the buffers that are not in the buffer list k scan the files given with the 'dictionary' option kspell use the currently active spell checking spell k**{dict}** scan the file {dict}. Several "k" flags can be given, patterns are valid too. For example:

        :set cpt=k/usr/dict/*,k~/spanish

s scan the files given with the 'thesaurus' option s**{tsr}** scan the file {tsr}. Several "s" flags can be given, patterns are valid too. i scan current and included files d scan current and included files for defined name or macro i_CTRL-X_CTRL-D ] tag completion t same as "]"

Unloaded buffers are not loaded, thus their autocmds :autocmd are not executed, this may lead to unexpected completions from some files (gzipped files for example). Unloaded buffers are not scanned for whole-line completion.

The default is ".,w,b,u,t,i", which means to scan:

1. the current buffer
2. buffers in other windows
3. other loaded buffers
4. unloaded buffers
5. tags
6. included files

As you can see, CTRL-N and CTRL-P can be used to do any 'iskeyword'- based expansion (e.g., dictionary i_CTRL-X_CTRL-K, included patterns i_CTRL-X_CTRL-I, tags i_CTRL-X_CTRL-] and normal expansions).

(default: ".,w,b,u,t,i")