"**SampleField\t This is the text of SampleField". Hidden stored fields are automatically stored in the index as document properties, and any text in a hidden stored field is not searchable. After a search, the values of any hidden stored fields will be returned in SearchResultsItem.UserFields for each item. 

Field names can include nesting, using / to separate field name elements. Example: "Meta/Subject\t This is the subject\tMeta/Authort This is the author" In this example, you could search across both fields by searching for "Meta contains (something)", or you could search for "Author contains (something)", or you could search for "Meta/Author contains (something)" to distinguish this Author field from any other Author fields that might be present in the document. 

If you are indexing documents, metadata in those documents will also be indexed as fields, so you may want to name your DocFields items to avoid clashes with common document metadata fields such as Title, Subject, Author, etc.