Dear Fil, I'm not sure what the example you provide shows - if I show a reader of English a "novel" sentence and they understand it without reference to the grammar, syntax, phonetics etc, I wouldn't be at all surprised. Show illustrations that include "nouns" (gears) and "verbs" (arrrows) in structure relationships is a language - yes. 700 technical words might take more time but that is a matter of choice just as the pictures are a matter of choice. (650 good words might take less?) If there were elements of "novelty" at the level of grammar and/or syntax in the illustration then I am sure the amount of time required to "read" the pictures would go up. Keith Russell OZ Newcastle >>>> Filippo A. Salustri I have a diagram of a gear system. There are a few text labels, but mostly the diagram is a bunch of partly or completely overlapping boxes with some arrows connecting them up. I show the diagram to a group of engineers. I tell them they have 15 seconds to study the diagram, and that I will then ask them questions. Cheers. Fil