Darn, I just typed a reply and lost it.
I only posted the 2 DRM's because the OP wanted company standards and those are the closest thing (especially Genium being based on GE) commercially available that I'm aware or. Most companies aren't going to give away an asset that takes considerable time and effort to prepare.
As to what is probably the real question:
I'd really start with the Industry standards. Genium & Global to some extend paraphrase or build upon the industry standards but can be pretty over whelming. We have them as a reference to our company DRM but don't directly invoke them, we basically just use them if they cover something the ASME specs don't.
Our DRM does some fine tuning/customization related to our interpretation of the standards in some cases, or how to do it with our CAD system. It's due a revision to add Model Based Definition.
If you are just trying to formalize what is the current 'best practice' at your current employer not necessarily introduce Industry Standards, then I'd look at a bunch of drawings that are regarded as 'good' and start from there.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:
What is Engineering anyway: faq1088-1484