1. An electronic bulletin board system including a server computer with an electronic bulletin board function communicating with at least one user computer via a network for mediating information exchange therebetween, said server computer comprising: a database as a notable words collection storing a plurality of words that are appropriately selected, each of the notable words in the database being linked with a corresponding URL; a logic device inspecting a message text sent from a user computer of a person who wants to post a message by consulting the notable words collection, wherein the inspected message text is posted on the bulletin board when the message text does not include a notable word in the notable words collection; and the notable word in the message text is converted into a hypertext format having a URL to which the word is linked as a link destination, and the message text is posted on the bulletin board when the message text includes a notable word in the notable words collection.