How to deduce the structure of 2,3-dihydroxybutanedioic acid

Thanks

All organic names are made of:

Root (number of carbons) - in this case but = 4
Suffix (nature of functional groups on chain) - in this case carboxylic acid
Prefix (any other functional groups) - in this case hydroxy group
Locants (where these functional groups are on the chain) - in this case the hydroxy groups are on positions 2 and 3
Multipliers (go before prefix and suffix to indicate more than one, eg di-, tri-, tetra-, etc) - in this case the carboxylic acid suffix has a "di" meaning "two of" and so does the hydroxy.

Put it all together:

HOOCCH(OH)CH(OH)COOH

Great, thanks! So if its '-dioic acid', is the COOH always on either end of the molecule?