You can use categories, provide different branches of knowledge with a different look (different template), use reference labels (Title, Author, Date, etc.) and clearly label subcategories (e.g. with strings such as chem for chemistry, math for mathematics, etc.). This will help you simplify the wording of your items as you will be relieved from the need to specify the context of your question. In the example below, the well-defined prefix bioch: saves you a lot of typing and a lot of reading while still making sure you do not confuse the abbreviation GRE with Graduate Record Examination. Note that in the recommended case, you process the item starting from the label bioch which puts your brain immediately in the right context. While processing the lesser optimum case, you will waste precious milliseconds on flashing the standard meaning of GRE and ... what is worse ... you will light up the wrong areas of your brain that will now perhaps be prone to interference!