GnuPG
PHP Manual

Predefined Constants

GNUPG_SIG_MODE_NORMAL ( integer )
GNUPG_SIG_MODE_DETACH ( integer )
GNUPG_SIG_MODE_CLEAR ( integer )
GNUPG_VALIDITY_UNKNOWN ( integer )
GNUPG_VALIDITY_UNDEFINED ( integer )
GNUPG_VALIDITY_NEVER ( integer )
GNUPG_VALIDITY_MARGINAL ( integer )
GNUPG_VALIDITY_FULL ( integer )
GNUPG_VALIDITY_ULTIMATE ( integer )
GNUPG_PROTOCOL_OpenPGP ( integer )
GNUPG_PROTOCOL_CMS ( integer )
GNUPG_SIGSUM_VALID ( integer )
GNUPG_SIGSUM_GREEN ( integer )
GNUPG_SIGSUM_RED ( integer )
GNUPG_SIGSUM_KEY_REVOKED ( integer )
GNUPG_SIGSUM_KEY_EXPIRED ( integer )
GNUPG_SIGSUM_KEY_MISSING ( integer )
GNUPG_SIGSUM_SIG_EXPIRED ( integer )
GNUPG_SIGSUM_CRL_MISSING ( integer )
GNUPG_SIGSUM_CRL_TOO_OLD ( integer )
GNUPG_SIGSUM_BAD_POLICY ( integer )
GNUPG_SIGSUM_SYS_ERROR ( integer )
GNUPG_ERROR_WARNING ( integer )
GNUPG_ERROR_EXCEPTION ( integer )
GNUPG_ERROR_SILENT ( integer )

GnuPG
PHP Manual