Permission Properties

By default, a tag's Access Mode property is set to Read/Write, which means that any user may read the value of the tag and may write to the tag. Read-only mode makes the tag non-writeable for all users.

Custom mode allows the tag to assign read/write or read-only privileges to individual roles. Any roles not explicitly granted a right by using the custom permissions editor will not be able to read the tag's value or write to the tag.