Here are some detailed explanations from the Help:
autonumber(expression[ , AutoID])
Returns a unique integer value for each distinct evaluated value of expression encountered during the script execution. This function can be used e.g. for creating a compact memory representation of a complex key.
In order to create multiple counter instances if the autonumber function is used on different keys within the script, an optional parameter AutoID can be used for naming each counter.
Examples:
autonumber( Region&Year&Month )
autonumber( Region&Year&Month, 'Ctr1' )
autonumberhash128(expression {, expression})
Calculates a 128-bit hash of the combined input expression values and the returns a unique integer value for each distinct hash value encountered during the script execution. This function can be used e.g. for creating a compact memory representation of a complex key.
Example:
autonumberhash128 ( Region, Year, Month )
autonumberhash256(expression {, expression})
Calculates a 256-bit hash of the combined input expression values and returns a unique integer value for each distinct hash value encountered during the script execution. This function can be used e.g. for creating a compact memory representation of a complex key. This function is only available as a script function.
Example:
Autonumberhash256 ( Region, Year, Month )
