I disagree. This is not a matter of the writers opinion. This is a SQLServer site and the question relates to SQLServer, not generic databases and structures. BOL clearly states that B-Tree stands for "Balanced". Sybase use the same definition and have done so for the 16 years I've been a dba. It was really Sybase who introduced the term, not MS, as far as I'm aware. I'm not arguing that anywhere else in the database world b-tree stands for binary, but relating to Sybase/SQLServer indexes it has always meant 'balanced'.

Cheers

Roddy