How can Anyone know if his idea is a new idea or an old one?
He could start facing the linguistic problems which come along while searching for the predecessor (e.g. using LikePages) or just expressing his own by giving it a name he chooses.
But where are the standards for describing knowledge or ideas? You should have linguistic rules for categorizing.. both grammar and syntax are meant: How to deal with CamelWords? ? Possible solutions are stemming (or splitting the composited words) and analysis of the semantic net of the vocabulary.
Does anyone have different ideas about that which are more than just the TextFormattingRules?
Sounds like you're talking about ontologies. The W3C is doing things in this direction for the SemanticWeb. One of those things is the WebOntologyLanguage. With regards to vocabulary analysis and classification, take a look at WordNet, at http://www.cogsci.princeton.edu/~wn/ . There's a whole world of research going on this direction right now. See also ResourceDescriptionFramework.