When a tape is seen as other it means the tape does not have a NetVault format on it and comes from another backup software or has been used by the operating system tape utility i.e. tar etc.
These tapes need to be blanked before NetVault can use them. In NetVault 10 it is not possible to blank these from the slot view.
To blank these tapes, select manage devices, select cog icon in line with library, select bulk blank, select tape other, enter password, enter BLANK and ok