For OpenSSL and GnuTLS valid examples of cipher lists include 'RC4-SHA', SHA1+DES, 'TLSv1' and 'DEFAULT'. The default list is normally get when you compile OpenSSL.
You'll find more details about cipher lists here: https://curl.haxx.se/docs/ssl-ciphers.html
For NSS, valid examples of cipher lists include 'rsa_rc4_128_md5', rsa_aes_128_sha, etc. With NSS you don't add/remove ciphers. If one uses this option then all known ciphers are disabled and only those passed in are enabled.
For WolfSSL, valid examples of cipher lists include ECDHE-RSA-RC4-SHA, 'AES256-SHA:AES256-SHA256', etc.