This General Electric Guideline is designed for print advertising and covers :
1.0 Brand Architecture
2.0 Monogram
3.0 Tagline
4.0 Color Palette
5.0 Typography
6.0 Imagery
7.0 Tone of Voice
8.0 Gray Bar
9.0 Transition Designs
10.0 Limited Space
11.0 Classifieds/Yellow Pages
12.0 Outdoor
13.0 Grids
There are many GE guidelines out there, since the company has a lot of activities, but I believe this is one of the most interesting PDFs.