http://resoapi.wfrmls.com/reso/odata/Properties?$filter=toupper(StreetName) eq 'MAIN'&$top=10&$select=ListingKeyNumeric,BedroomsTotal,Directions,ListingContractDate,ModificationTimestamp,StandardStatus,PropertyType,PublicRemarks,StreetName
Convert a string to upper case (toupper). Lower case would use the function tolower().