Linking an external document to a period

https://help.myob.com/wiki/x/8h_EAQ

You can link an external document to a period where the document doesn't relate to a specific account.

Go to the client’s Client Accounting > Trial Balance (Workpapers) tab and click a period in the Select Period section.
On the TASKS bar, click Open Period. The table for the period appears.
Click the Non-account specific documents checkbox. This is the first item listed in the table.
On the TASKS bar, click Link Document. The Attach External File window appears.
Select a file and click Open.
The Link External File window appears.
Leave the Account field blank.
Optionally, if you want to link to a bookmark in your document, select a Reference value.
If you want to rollover the document into the next period, select Rollover this document to the next period checkbox.
Click Link.
The external file is displayed as a sub-row below Non-account specific documents in the table. A paperclip iconidentifies a linked document.