Disclosed herein is a heat transfer fluid, comprising a hydroxylated carboxylic acid of formula xy, wherein x is 2 to 10, y is 3 to 10, and R1 is a C2-50 aliphatic group, a C6-50 aromatic group, or a combination thereof; and wherein the hydroxylated carboxylic acid comprises the hydroxylated carboxylic acid, an ester thereof, a salt thereof, an anhydride thereof, or a combination thereof. To achieve a common data format, the invention uses a data format which includes character strings and contains a Boolean expression, the Boolean expression being able to be allocated to at least one result as a function rule. The inner portion is made of the first material. To achieve this, the PCB must first travel backwards into the rack-mounted assembly, and then downwards into engagement with the backplane.