Possible Duplicate:
Tag hierarchy to browse through tags

I would be very happy to see tags tree-like relation. For example if I'm not interested in SQL discussions on StackOverflow, I can add SQL to my ignored tags. But questions have a number of different tags like MySQL, PostgreSQL, MSSQL, MSSQL4.5, MSSQL8.4, MSSQL2014-SP4 etc. If they were in tree-like structure I could ignore #sql tag and that would exclude all SQL questions. Ignoring #javascript could auto-exclude #jquery, #ajax etc.