This is the old "special" license: https://github.com/openssl/openssl/blob/OpenSSL_1_1_1c/LICENSE https://github.com/openssl/openssl/blob/OpenSSL_1_1_1c/LICEN.

This is the old "special" license: https://github.com/openssl/openssl/blob/OpenSSL_1_1_1c/LICENSE https://github.com/openssl/openssl/blob/OpenSSL_1_1_1c/LICEN... And this is likely the condition the article refers to 3. All advertising materials mentioning features or use of this software must display the following acknowledgment: "This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit. (http://www.openssl.org/)" The original SSLeay license included in that same license had a similar requirement.