Add obsolete phone to contact I have old messages from contact sent using temporary phone number he had on vacation. I want those messages grouped under his name in conversations, so I added it as another number to contact details. Messages are now fine, but this "obsolete" number is now clutters phone list when I tap on contact and need to chose what number to dial.

Is there a way to add a number to contact, but make it not appear in list of numbers to call when you select contact?

As first answer mentions, I can set other phone as default, but this still leaves obsolete phone on contact summary page and you can still accidentally call it with mis-click. I'd really like it to only show on contact edit page and be uncallable or at least not without confirmation prompt.
You can select a number as "default" or "main" and then this number will be dialed when you call that person. 

Usually it can be done by long tap on a number and then selecting "Set as default".