Hidden feature of VisualStudio

I came across a blog entry regarding a hidden feature of VisualStudio (I cannot find the entry again). By adding a registry entry it is possible to let VisualStudio display vertical lines in the code viewer. This is a useful reminder to limit the number of characters per line (so that the print-out become more legible). You can try it out following the instructions below:

• find the registry entry: [HKEY_CURRENT_USER]\Software\Microsoft\VisualStudio\7.1\Text Editor
• add a string with the name "Guides" and the value "RGB(128,0,0) 90"
• restart VisualStudio

This instruction works for version 2003, but by editing a similar registry entry it should work for versions 2002 and 2005 as well. The above gives a red line at column 90.