`--synctex=n`

  Generate &SyncTeX; data for previewers. If n is zero, no `.synctex` file is created. If n is negative, the `.synctex` file is a text file. If n is positive, the `.synctex` file is compressed with `gzip` and the `.gz` file name extension is added.

  --synctex=n

  Furthermore, n is interpreted as a bit field:

  Bit 1 (n AND 2)

    Don't add the `.gz` file name extension.

  Bit 2 (n AND 4)

    Activate form support.

  Bit 3 (n AND 8)

    Activate better compression.