/usr/share/vim/addons/plugin/moin.vim is in editmoin 1.17-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | au! BufRead,BufNewFile *.moin
\ if getline(1) =~ '^@@ Syntax: 1\.5$' | setf moin1_5
\ | else | setf moin1_6 | endif
|