The MHL Tool encompasses operations to be performed with both MHL V.1 and ASC MHL seals. These operations include Creating a New Seal, Resealing, and Verifying. 

Create a New Seal will appear when an item without an existing MHl seal is added to the queue. Once you have selected the option to Create a New Seal, you will be asked to select the type of seal created, either MHL V1 or ASC MHL.

If you select MHL V1 you will also be asked to select its placement. Your options are to include it as a Sidecar (outside of the referenced folder of files) or Embedded in the sealed directory.

Resealing an item appears when adding an item with an already existing MHL seal into the queue. When resealing an item the type of seal must remain the same, but you will be able to make changes to the checksum types included. 

If new checksum algorithms are added to a subsequent generation, at least one of the previous algorithms must be used to maintain the seal’s integrity. This option will result in the creation of a new seal file.

The Verify option appears similar to the Reseal option, when adding an item with an already existing MHL seal into the queue. 

For this operation you are unable to change any of the settings but instead can perform a check to make sure the existing seal is still valid and has remained unbroken. This will report any detected issues with the seal but will not generate a new seal file.