We know what accepting something at “face value” means. On the one hand it has to do with crediting someone for the amount of money as shown on the face of the paper bill, or in other words giving someone ten dollars worth of goods for the paper in the person’s hand that shows a face value of ten dollars, the “face” being that of Jefferson. The phrase has also come to mean accepting what someone says without analysis or judgment. It is a statement of belief, that whatever you say I will believe, at least for now. It is a statement of trust that the face behind the words you hear is one that you trust and will therefore accept the words as truth or fact.
Accepting at word value is similar, without the belief and trust stuff. Accepting at word value is a way of validating the words as they are written (or said) and not making an assumption of what the words really mean. Accepting at word value is also a humorous game. For example, someone asks, “How does your April look?” meaning, of course, idiomatically, “what’s your availability in April?” However, taken at word value, the response might be, “Oh, it’s about thirty days long, usually on the warmish side, and typically has Passover and Easter holidays in it”. The humor is in taking the words literally rather than assuming the intended meaning.
If you were to read and review everything you write at word value, you will discover many instances of idiomatic expressions or included assumptions. This is OK for conversation where the responder can ask for clarification or make light of the expression. In written communication it can become dangerous when you include what you consider as an obvious allusion which the reader is not aware of. The primary assumption in writing, especially business writing and most especially requirements writing, is that the reader will interpret the words exactly as they are written, in other words, take them at word value. Exacerbating the issue is the “value” they may place on the word. Whereas the face value of a ten dollar bank note is always ten dollars, regardless of the actual value in purchasing power, the “value” or meaning of the word may differ from reader to reader and this brings up the issue of ambiguity, which is also a great source of humor.
Read your document at word value without reading your intended meaning into it. When you see a different meaning, don’t assume that “no one will interpret it this way. The real meaning of the words is obvious”. Instead change the word and increase the value, that is, make the value equal to your intention.