Sometimes, we get questions about schematics from vendor application notes, datasheets, and such. You'd think that simply clipping the schematic from the appnote and inserting it as an image'd do, right?
Well, some vendors (older LTC and NatSemi application schematics are notorious for this, but I suspect a few others do it as well) don't use a full system of reference designators on their appnote schematics -- I suspect they were drafted using regular CAD tooling or such instead of an EDA tool, and that this was also intentional to avoid confusing people who refdes differently. However, they sometimes leave a few reference designators in and/or use nonstandard reference designators as well (Linear likes to call a comparator IC 'C1' sometimes, for instance, but will call a capacitor 'C1' in other schematics of theirs, and will even designate a combination of parts with a single reference designator. See below for an example (from LTC AN43) of the latter two).
Should we insist on making people either redraw a vendor circuit in CircuitLab (with a rather high potential for lossage due to CircuitLab being missing funny symbols and the likes) or scribble on the clipped image with an image editor to "pencil in" their own system of reference designators (with potential for confusion due to having 1.5 reference designator systems on 1 schematic)? Or should we try to "talk around" the infelicity of not having reference designators instead of trying to make the OP clean up vendor divots (which can be a PITA if you're on mobile)?