Article 8 of the Trademark Law stipulates: "Any visible sign that can distinguish the goods of a natural person, legal person or other organization from those of others can apply for registration as a trademark." This article requires that trademarks must be recognizable and visible. Article 1 9 of the Trademark Law stipulates: "A trademark applied for registration shall have distinctive features and be easy to identify, and shall not conflict with the legal rights previously obtained by others." In this article, "should have distinctive features" means that it requires distinctiveness and "must not conflict with other people's prior legal rights", that is, it requires legality, which is also called "non-conflict". Therefore, items A, B and C are the constitutive conditions of trademarks. Trademark does not necessarily require aesthetic feeling, so item D is incorrect.