(dizz)

An ASCII text file containing a description of the programs included in the same ZIP archive. This information will typically be in a file called FILE_ID.DIZ. The FILE_ID.DIZ description standard has been abandoned and is no longer supported by any official body.

If you get a .DIZ file try opening it in a text editor and see if the contents can be easily read. If not, ask the person who sent it what program to use to open it.