Don't try to hide your age in the "Classmates", making the profile available only for friends. The rest will not available almost all information about you, even the portrait will appear reduced without possibility of increasing. But age will still see everything.
In the mobile version of "Odnoklassniki" to change privacy settings not in the settings menu there is no corresponding item. If you have this social network is blocked, and a home or mobile Internet although unlimited, but too slow to use full version, or you use a mobile device with low computational power, install while "unreal" year of birth so as to display age were either too large (110 years or more) or too small (two to three years). Date of birth do not change, you still can congratulate him happy birthday. To change the year of birth through the menu as follows: "Other sections" - "Settings" - "Personal data". Adjust the year of birth and then click "Save".
If you have high-speed unlimited Internet access from your computer (or mobile device, the computing power which is sufficient to display the full version of "Classmates") in settings it is possible to completely disable the display of age. While in the full version of the web interface, click the "More" menu, and there will be additional items. Select "Change settings" and then "Preferences publicity". Now find the line "Age", and in it, select one of the three desired options: "all", "Only friends" or "Only me." Click "Save".
If you wish to make your age could see everyone, you can always change it back. If you changed the birth year on the "unreal", change it back to the present. If you did age visible only to friends or yourself, make it visible again "all". Save the settings. Remember to sign out of social networks when not using.