Hi Adam,
These source codes have probably been mistakenly created due to valid source codes in GL not having been created prior to retrieving the first sub-ledger batch into GL. Note that for these 2 source codes in GL, the first two characters of the source code description are the same as one of your Cashbook bank codes.
As you know, the source code that GL uses for Cashbook is CB-XX where XX is the bank code.
Because these source codes start with two blank spaces, they are uneditable and cannot be deleted. They have to be considered as 'corrupt' data, and if you want them removed, a database repair is the only way to do this.
Regards,
Softrak Support