can not create a column family named 'index'

[Shu Zhang]

Hi, just wondering if this is intentional:

[default@test] create column family index;
Syntax error at position 21: mismatched input 'index' expecting set null
[default@test] create column family idx;
b9aae960-1bb2-11e1-0000-bf27a177f2f6
Waiting for schema agreement...
... schemas agree across the cluster

Thanks,
Shu