I don't see this topic was resolved. Now with phpBB 3.0.11 out, I am still looking for an answer.
I require birthdates (including year) because of the COPPA requirement (
http://www.ftc.gov/privacy/coppafaqs.shtm and
http://www.coppa.org/). Because we gather information (such as email, etc.), I need parental consent from the users under 13 for compliance purposes.
However, when it comes to birthdates, even if the "Display Age" is set to "No" or the Birthday Congrats is set to "No", I am still seeing the users' ages being posted.
Before I upgraded to 3.0.11, I finally decided to heck with it and completely removed the portion where it displayed the age in the Birthday Congrats area. However, I forgot what I had done. Furthermore, it seems a lot of the 3.0.11 modifications to the core script have been completed, rendering it difficult for previous MODS to be installed since the verbage has changed.
I look forward to a working solution, other than simply removing the "(Age)" part when it's your birthday.