ssh-add Options (SSH, The Secure Shell: The Definitive Guide)

B.9. ssh-add Options

SSH1	SSH2	OpenSSH	Option	Meaning
			-1	Limit SSH1 compatibility
			-d	Unload key
			-D	Unload all keys
			-f step	Limit agent-forwarding hops
			-F host_list	Limit agent-forwarding hosts
			-I	PGP keys are identified by ID
			-l	List loaded keys
			-l	List fingerprints of loaded keys
			-L	Lock agent
			-L	List loaded keys
			-N	PGP keys are identified by name
			-p	Read passphrase from stdin
			-P	PGP keys are identified by fingerprint
			-R filename	Specify PGP keyring file
			-t timeout	Expire key after timeout
			-U	Unlock agent