The indexed ItemId thing is a basic and elementary concept related with the basics of table relationships.
Mirc coders could create a hadd function instead a procedure. That $hadd(table, key, value) would return a key Id and then we could address the possibly long key from other tables through its Id
Tables for Key Identification are called to be 1NF tables and its ID's are used in other tables for attribute setting, while the attribute setting of 1NF tables does not exist or if it is required as it would be in the $hadd function then is set to a single alphanumeric character just to fulfill the attribute requirement
Are my explanationsbeing too complex ?
You can find countless pages about table basic normalization.