The Less Than Or Equal To operator is used to compare two numeric values, it is used for fields which represent:
It will return all records where the fields value is less than or equal to the supplied value.
Values are normally either unquoted numbers, or quoted date time or time span values.
All requirements with less than or equal to 1 associated script
EntityType = Requirement AND TestScriptsCount <= 1
All requirements created before 2011
EntityType = Requirement AND CreatedAt <= '2010-12-31'
All scripts created at least one week ago
EntityType = Script AND CreatedAt <= '-1w'
All script assignments where the estimated duration is less than or equal to 5 minutes (Note: you can write time values as either '5m' or '5 minutes' or '00:00:05')
EntityType = ScriptAssignment AND EstimatedDuration <= '5m'