[ms-xlsx]: Excel (. xlsx) Extensions to the Office Open xml spreadsheetml file Format

bottom: A Boolean ([XMLSCHEMA2] section 3.2.2) attribute that specifies how the conditional formatting rule is applied as specified by the following table. This attribute MUST NOT exist if type is not equal to "top10".

Value	Meaning
"true"	Conditional formatting is applied to cells whose value is in the bottom end of the range specified by percent and rank.
"false"	Conditional formatting is applied to cells whose value is in the top end of the range specified by percent and rank.

operator: An ST_ConditionalFormattingOperator ([ISO/IEC29500-1:2011] section 18.18.15) attribute that specifies the type of value comparison used for this conditional formatting rule. This attribute MUST NOT exist if type is not equal to "cellIs".