In General Ledger Entries there is a field called "System-Created".
If you used the G/L account directly then this field (which is not shown by default) is set to false.
If it is used indirectly, through a customer/vendor ..., then it shoudl be set to true.
Next indicator could be the "Source Type" & "Source No.".
These fields shoul not be filled if you created the G/L Entry directly.