Understanding Siebel attachment file name

Hi,

I'd like to understand the Siebel attachment file name convention.

example:

S_ACCNT_ATT_9SIA-9LHNL_9SIA-J7ER.SAF

so there is 3 parameters separated by the underscore character plus the file extension (.SAF)

I guessed the first 2 parameters:

<Table Name>

<Row Id of the Attachment>

what is 3rd one? it seems to be a Row Id

It's not the Row Id of the User who created the attachment and it's not the Row Id of the parent record (i.e. the account)

thanks

Matthieu