+.B VERSION {2|3}
+Specifies what version of the LDAP protocol should be used.
+.TP
+.B TIMEOUT <integer>
+Specifies a generic timeout (in seconds). Currently ignored.
+.SH SASL OPTIONS
+If OpenLDAP is built with Simple Authentication and Security Layer support,
+there are more options you can specify.
+.TP
+.B SASL_MECH <mechanism>
+Specifies the SASL mechanism to use.
+.B This is a user\-only option.
+.TP
+.B SASL_REALM <realm>
+Specifies the SASL realm.
+.B This is a user\-only option.
+.TP
+.B SASL_AUTHCID <authcid>
+Specifies the authentication identity.
+.B This is a user\-only option.
+.TP
+.B SASL_AUTHZID <authcid>
+Specifies the proxy authorization identity.
+.B This is a user\-only option.
+.TP
+.B SASL_SECPROPS <properties>
+Specifies Cyrus SASL security properties. The
+.B <properties>
+can be specified as a comma-separated list of the following:
+.RS
+.TP
+.B none
+(without any other properties) causes the properties
+defaults ("noanonymous,noplain") to be cleared.
+.TP
+.B noplain
+disables mechanisms susceptible to simple passive attacks.
+.TP
+.B noactive
+disables mechanisms susceptible to active attacks.
+.TP
+.B nodict
+disables mechanisms susceptible to passive dictionary attacks.
+.TP
+.B noanonymous
+disables mechanisms which support anonymous login.
+.TP
+.B forwardsec
+requires forward secrecy between sessions.
+.TP
+.B passcred
+requires mechanisms which pass client credentials (and allows
+mechanisms which can pass credentials to do so).
+.TP
+.B minssf=<factor>
+specifies the minimum acceptable
+.I security strength factor
+as an integer approximating the effective key length used for
+encryption. 0 (zero) implies no protection, 1 implies integrity
+protection only, 56 allows DES or other weak ciphers, 112
+allows triple DES and other strong ciphers, 128 allows RC4,
+Blowfish and other modern strong ciphers. The default is 0.
+.TP
+.B maxssf=<factor>
+specifies the maximum acceptable
+.I security strength factor
+as an integer (see
+.B minssf
+description). The default is
+.BR INT_MAX .
+.TP
+.B maxbufsize=<factor>
+specifies the maximum security layer receive buffer
+size allowed. 0 disables security layers. The default is 65536.
+.RE
+.SH TLS OPTIONS
+If OpenLDAP is built with Transport Layer Security support, there
+are more options you can specify. These options are used when an
+.B ldaps:// URI
+is selected (by default or otherwise) or when the application
+negotiates TLS by issuing the LDAP StartTLS operation.
+.TP
+.B TLS_CACERT <filename>
+Specifies the file that contains certificates for all of the Certificate
+Authorities the client will recognize.
+.TP
+.B TLS_CACERTDIR <path>
+Specifies the path of a directory that contains Certificate Authority
+certificates in separate individual files. The
+.B TLS_CACERT
+is always used before
+.B TLS_CACERTDIR.
+.TP
+.B TLS_CERT <filename>
+Specifies the file that contains the client certificate.
+.B This is a user\-only option.
+.TP
+.B TLS_KEY <filename>
+Specifies the file that contains the private key that matches the certificate
+stored in the
+.B TLS_CERT
+file. Currently, the private key must not be protected with a password, so
+it is of critical importance that the key file is protected carefully.
+.B This is a user\-only option.
+.TP
+.B TLS_CIPHER_SUITE <cipher-suite-spec>
+Specifies acceptable cipher suite and preference order.
+<cipher-suite-spec> should be a cipher specification for OpenSSL,
+e.g., HIGH:MEDIUM:+SSLv2.
+.TP
+.B TLS_RANDFILE <filename>
+Specifies the file to obtain random bits from when /dev/[u]random is
+not available. Generally set to the name of the EGD/PRNGD socket.
+The environment variable RANDFILE can also be used to specify the filename.
+.TP
+.B TLS_REQCERT <level>
+Specifies what checks to perform on server certificates in a TLS session,
+if any. The
+.B <level>
+can be specified as one of the following keywords:
+.RS
+.TP
+.B never
+The client will not request or check any server certificate.
+.TP
+.B allow
+The server certificate is requested. If no certificate is provided,
+the session proceeds normally. If a bad certificate is provided, it will
+be ignored and the session proceeds normally.
+.TP
+.B try
+The server certificate is requested. If no certificate is provided,
+the session proceeds normally. If a bad certificate is provided,
+the session is immediately terminated.
+.TP
+.B demand | hard
+These keywords are equivalent. The server certificate is requested. If no
+certificate is provided, or a bad certificate is provided, the session
+is immediately terminated. This is the default setting.
+.RE
+.TP
+.B TLS_CRLCHECK <level>
+Specifies if the Certificate Revocation List (CRL) of the CA should be
+used to verify if the server certificates have not been revoked. This
+requires
+.B TLS_CACERTDIR
+parameter to be set.
+.B <level>
+can be specified as one of the following keywords:
+.RS
+.TP
+.B none
+No CRL checks are performed
+.TP
+.B peer
+Check the CRL of the peer certificate
+.TP
+.B all
+Check the CRL for a whole certificate chain
+.RE
+.SH "ENVIRONMENT VARIABLES"
+.TP
+LDAPNOINIT
+disable all defaulting
+.TP
+LDAPCONF
+path of a configuration file
+.TP
+LDAPRC
+basename of ldaprc file in $HOME or $CWD
+.TP
+LDAP<option-name>
+Set <option-name> as from ldap.conf