Examiners seem to be going crazy lately over drawing objections.
(1) In one application, I recently got my first (in six years+ practice) "every element of the invention not shown in a drawing" objection. Including objections for dependent method claims for basically software inventions.
(2) In a second application, I got my first "drawing not labelled prior art" objection. In support of software applications, I show a basic block diagram with processor, memory, data storage device, I/O ports, ....I've never had any problems with this. And I've seen a zillion issued patents with variations of this theme. Now I have an Examiner insisting that it be labelled "prior art". I have to argue that it executes a new algorithm.
(3) In a third application, I got my first "missing descriptive text in drawing" objection. This was a crowded circuit diagram, primarily using standard circuit element symbols, each properly labelled with a callout reference number. A few elements were depicted as rectangles, circles, , triangles, or hexagons. I found out that there's an obscure requirement in the MPEP that rectangular boxes be labelled with descriptive text: this rule applies only to rectangular boxes! I had to file replacement drawings with a text label on each rectangular box, but not on the circles, triangles, and hexagons.
The "every element of the invention must be shown in a drawing" requirement is absurd. Using one of our favorite examples, if I have a dependent claim "...wherein the fastener is a screw, a nail, or a rivet", I would need a drawing showing a screw, a nail, and a rivet.
I don't even comprehend the part of 37 CFR 1.81(c) which says essentially that even when drawings are not necessary to understand the invention, but the invention is capable of being illustrated, then the Examiner can require drawings. Why? As discussed here, any invention is capable of being illustrated. For software, enter text or equations in boxes and label "Fig. 1". But what purpose do the drawings serve?