Wikipedia
WYSIWYM (an acronym for "what you see is what you mean") is a paradigm for editing a structured document. It is an adjunct to the better-known WYSIWYG (what you see is what you get) paradigm, which displays a formatted document on screen as it will appear in only one mode of presentation.
In a WYSIWYM editor, the user writes the contents in a structured way, marking the content according to its meaning, its significance in the document, leaving its final appearance up to one or more separate style sheets. For example, in a WYSIWYM document a human being manually marks text as the title of the document, the name of a section, or the name of an author; this would in turn allow one element, such as section headings, to be rendered as large bold text in one style sheet, or as red center justified text in another, without further human intervention. This requires the semantic structure of the document to be decided on before writing it. The editor also needs a system for exporting structured content to generate the document's final format, following the indicated structure.
The main advantage of this system is the total separation of presentation and content: users can structure and write the document once, rather than repeatedly altering it for each mode of presentation, which is left to the export system.
What you see is what you meant (WYSIWYM) is a text editing interaction technique that emerged from two projects at University of Brighton. It allows users to create abstract knowledge representations such as those required by the Semantic Web using a natural language interface. Natural language understanding (NLU) technology is not employed. Instead, natural language generation (NLG) is used in a highly interactive manner.
The text editor accepts repeated refinement of a selected span of text as it becomes increasingly less vacuous of authored semantics. Using a mouse, a text property held in the evolving text can be further refined by a set of options derived by NLG from a built-in ontology. An invisible representation of the semantic knowledge is created which can be used for multilingual document generation, formal knowledge formation, or any other task that requires formally specified information.
The two projects at Brighton worked in the field of Conceptual Authoring to lay a foundation for further research and development of a Semantic Web Authoring Tool (SWAT). This tool has been further explored as a means for developing a knowledge base by those without prior experience with Controlled Natural Language tools.