The term hierarchical classification system is identified in base64 scheme by the sequence aGllcmFyY2hpY2FsIGNsYXNzaWZpY2F0aW9uIHN5c3RlbQ==, while the MD5 signature is equal to ed96c1f64591c623619e2ed0a33c0ae4. The ASCII encoding of hierarchical classification system in hexadecimal notation is 68696572617263686963616c20636c617373696669636174696f6e2073797374656d.