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#### 3.2.4 OpenPGP protocol specific options.

`-t, --textmode`
`--no-textmode`
  Treat input files as text and store them in the OpenPGP canonical text form with standard "CRLF" line endings. This also sets the necessary flags to inform the recipient that the encrypted or signed data is text and may need its line endings converted back to whatever the local system uses. This option is useful when communicating between two platforms that have different line ending conventions (UNIX-like to Mac, Mac to Windows, etc). `--no-textmode` disables this option, and is the default.
`--force-v3-sigs`
`--no-force-v3-sigs`
  OpenPGP states that an implementation should generate v4 signatures but PGP versions 5 through 7 only recognize v4 signatures on key material. This option forces v3 signatures for signatures on data. Note that this option implies `--no-ask-sig-expire`, and unsets `--sig-policy-url`, `--sig-notation`, and `--sig-keyserver-url`, as these features cannot be used with v3 signatures. `--no-force-v3-sigs` disables this option. Defaults to no.
`--force-v4-certs`
`--no-force-v4-certs`
  Always use v4 key signatures even on v3 keys. This option also changes the default hash algorithm for v3 RSA keys from MD5 to SHA-1. `--no-force-v4-certs` disables this option.
`--force-mdc`
  Force the use of encryption with a modification detection code. This is always used with the newer ciphers (those with a blocksize greater than 64 bits), or if all of the recipient keys indicate MDC support in their feature flags.
`--disable-mdc`
  Disable the use of the modification detection code. Note that by using this option, the encrypted message becomes vulnerable to a message modification attack.
`--personal-cipher-preferences string`
  Set the list of personal cipher preferences to `string`. Use `gpg2 --version` to get a list of available algorithms, and use `none` to set no preference at all. This allows the user to safely override the algorithm chosen by the recipient key preferences, as GPG will only select an algorithm that is usable by all recipients. The most highly ranked cipher in this list is also used for the `--symmetric` encryption command.
`--personal-digest-preferences string`
  Set the list of personal digest preferences to `string`. Use `gpg2 --version` to get a list of available algorithms, and use `none` to set no preference at all. This allows the user to safely override the algorithm chosen by the recipient key preferences, as GPG will only select an algorithm that is usable by all recipients. The most highly ranked digest algorithm in this list is also used when signing without encryption (e.g. `--clearsign` or `--sign`).
`--personal-compress-preferences string`
  Set the list of personal compression preferences to `string`. Use `gpg2 --version` to get a list of available algorithms, and use `none` to set no preference at all. This allows the user to safely override the algorithm chosen by the recipient key preferences, as GPG will only select an algorithm that is usable by all recipients. The most highly ranked compression algorithm in this list is also used when there are no recipient keys to consider (e.g. `--symmetric`).
`--s2k-cipher-algo name`
  Use `name` as the cipher algorithm used to protect secret keys. The default cipher is CAST5. This cipher is also used for symmetric encryption with a passphrase if `--personal-cipher-preferences` and `--cipher-algo` is not given.
`--s2k-digest-algo name`
  Use `name` as the digest algorithm used to mangle the passphrases. The default algorithm is SHA-1.
`--s2k-mode n`
  Selects how passphrases are mangled. If `n` is 0 a plain passphrase (which is not recommended) will be used, a 1 adds a salt to the passphrase and a 3 (the default) iterates the whole process a number of times (see –s2k-count). Unless `--rfc1991` is used, this mode is also used for symmetric encryption with a passphrase.
`--s2k-count n`
  Specify how many times the passphrase mangling is repeated. This value may range between 1024 and 65011712 inclusive. The default is inquired from gpg-agent. Note that not all values in the 1024-65011712 range are legal and if an illegal value is selected, GnuPG will round up to the nearest legal value. This option is only meaningful if `--s2k-mode` is 3.