git ignore exception

To exclude everything in a directory, but some sub-directories, do the following:

wp-content/*
!wp-content/plugins/
!wp-content/themes/

Source: https://gist.github.com/444295

You can simply git add -f path/to/foo.dll.

.gitignore ignores only files for usual tracking and stuff like git add .

Git ignores folders if you write:

/js

but it can't add exceptions if you do: !/js/jquery or !/js/jquery/ or !/js/jquery/*

You must write:

/js/* 

and only then you can except subfolders like this

!/js/jquery

Use:

*.dll    #Exclude all dlls
!foo.dll #Except for foo.dll

From gitignore:

An optional prefix ! which negates the pattern; any matching file excluded by a previous pattern will become included again. If a negated pattern matches, this will override lower precedence patterns sources.