>>
>>TBH, I'm not a fan of using multiple fields for a PK (always assuming this is one of course).
>
>I had never assumed this to be for a PK - which I always argue to be a LongInt where possible or an Integer in vfp. No reason to "meaningfully sort" on a PK in my book, as they should be devoid of info.
>
>>And if you stick to one field then whether you reformat the field or bodge an index on the existing format you still have to enforce the rules for subsequent data entry.
>
>Yupp, but this is much easier to communicate throughout documentation if there are 2 fields each with a different spec.

There's also a bigger flaw in the PADL ideas - fields such as 'HMD1' and 'HMD01' will be identical.....