ruby::conditions => “LIKE ___%” syntax

The following gives an error:

ArgumentError:
 malformed format string - %'

:

[code] named_scope :sales, :conditions => ["rolename LIKE 'salesteam%'"]

The following is OK:

[code] named_scope :sales, :conditions => ["rolename LIKE 'salesteam%%'"]

I am wondering where I can find the documentation for the

%%

(double
%) syntax.