Monthly Archives: June 2014

My users don’t care what department their colleagues are in.

Or – how to hide columns from the GAL view in the outlook 2010 address book.

Just had an interesting call regarding the GAL in Exchange 2010 and Outlook 2010. I have a customer who doesn’t want users to know what department their colleagues are in. I don’t ask why. People baffle me sometimes. Can we do this? Yes we can. Have a look at this article in the knowledgebase. Yes, I know it’s for outlook 2007, but this sort of thing is so esoteric no-one can be bothered updating it for Outlook 2010. Will it work for outlook 2010? Yes it will.

First, open regedit and browse to HKCU\Software\Microsoft\Office\14.0\Outlook\Preferences, and create the ABHiddenColumns binary value key.

I’m not going through it, it’s exactly the same as in the KB article.

Right click the ABHiddenColumns key, select modify and type in the chosen value, as per the table in the KB article. So far, so much regurgitated content. The bit that is missing from the article is the value you need to remove the “Department” column. This can be found in the big book of MAPI stuff, volume eleventeen, “[MS-OXOAB]: Offline Address Book (OAB) Format and Schema Protocol Specification


Trouble is, that value is bigendian, and it needs to be little-endian. Or possibly the other way around. Whatever, you need to reverse the order of the octets and lose the leading 0x. so 0x3A18001F becomes 1F00183A. Add it to the 0#000000 that the article talks about (where # is the number of values you want to hide; in this case “1”) and you get 010000001F00183A. Just type that string in; no need to format it or add spaces or anything else, regedit takes care of all the magic.


Click “OK”, restart outlook and hey presto! this:


Becomes this:


“Department” is gone. This works in cached mode and online mode. So… what have I told you that’s new? not a lot. It works for outlook 2010, and there’s a way to get rid of a column that they strangely miss in the article. How do you apply it to 30,000 users? Group policy, my friend. How do you get rid of it in OWA? Custom html page, would be my guess. I’ve not done it, but that’s where I’d start.