Sharing
It is important that staff take responsibility and care when setting sharing settings. Staff have access to considerable confidential information and even accidentally sharing with a third party could have serious consequences.
In general:
The preferred share setting is "Restricted, only people added can access this link" and then share to specific groups
Nothing should be shared outside the domain bisphuket.ac.th
Nothing should ever be shared to students personal email addresses only to their school account
No documents in staff shared drives should be shared with students. Staff should make a copy in their own drive and share from there
It is best to organise folders so that it is clear which documents are shared and with whom.
Requests to grant access a document from a non-school email address should normally be rejected.
The most common problem with accessing school documents is use of the incorrect Google account. Although it is possible to open multiple accounts at the same time, Google does not always use the account you are expecting. It is simplest to log into one Google account at a time.
Owner
Every document has an owner, the owner is the only person who can permenently delete a document. However even after a document has been "Removed" it remains accessible to people it is shared with until it is finally deleted (usually after 30 days, quicker if the user empties the trash).
Secondly the document will be deleted permenently if the owners Google account is deleted. It is critical that before they leave the school a teacher transfers ownership of any important documents to a colleague.
The exception is that any document in a shared drive is owned by the shared drive rather than a user. Shared drives are the recommended place to store important documents, because they remove the risk of accidental deletion when a teacher leaves.