I learned of this website from a presentation by Duane Barrett with Bentley Systems.

He did the presentation during a Design in '09 Federal Infrastructure Spending Builds BIM Opprotunities Seminar hosted by ModernTech AEC Solutions in Atlanta, GA.

Welcome to the USACE Centers of Standardization (COS) website:
https://eportal.usace.army.mil/sites/cos/pages/default.aspx

All MicroStation Versions

Dimension Tips
Dimension extension line attributes may be adjusted within a dimension string.
Note: This tip is also in this Wiki:  http://communities.bentley.com/Communities/Other_Communities/AskInga/w/AskInga/change-symbology-of-extension-lines.aspx
Here are the steps:
1. First set the extension line and dimension line attributes to a desired setting, (extension line style 4, dimension line style…