I was always confused about the scribbles on Bus Bomb letter. First black scribble is in left down corner of the page and second one is on page 3. At first sight, those scribbles seems to be absolutely useless, with no meaning at all. But I would recommend to think about them a bit more deeply (especially since they appear on few other pages of his letters too). Is it possible they might be important?
1.) let´s try to think as perpetrator for a few mins, ok? We have no idea about Zodiac´s job, so we dont know if he used papers in his own job, but as anyone else, he used papers in his own common (non-killer) life. It means that he had to separate papers into two groups which could not mix…. Common papers (where everything including his fingerprints can appear) and papers he used as Zodiac – and he probably worked with them in gloves, otherwise there would be tons of known Zodiac fingerprints. Then – how those black lines got to those papers when he wrote the main letter in blue ink?
2.) crucial point I´d like to point out is difference between left down corner scribble and the one which is at the segment of page with "must print in the paper"… they are very different. For a moment, let´s imagine that he wrote various versions of his letters – something like conceptual versions and final ones and that those pages overlaped for a moment – and something he drawn on unused "concept" version accidently got on the page he later used for final letter. That would explain the first page scribble, because it gets precisely to the edge of page. But that´s not case of 3rd page scribble – at the 3rd page it looks like that "something straight" was blocking the left edge of paper, because it starts and ends at the very same "distance" from edge of paper. The question also is about the "start" and "end" of that particular line, because it seems that it starts round and ends round (not flat which would indicate overlapping papers). If you use a pencil or ballpoint pen, it starts line with round and it ends line with a round edge. When you have overlapping papers and write across them – the line on paper below will start with blunt end, not circular one. What this would mean? My deduction (if start and end is really round as it looks like from all pictures of that letter) would mean, that especially the line on 3rd page is intentional and therefore – it may have a meaning.
3.) at the same pages (one and three) are two very small symbols written in right bottom corner (and they seems to be written pretty carefully by pencil). Was meaning of them ever investigated? Once again – I´m asking because he obviously had to separate "normal" papers used in normal life and papers used for his Zodiac spree.
4.) I cannot find HQ enough version of letter with 340 Cipher – that letter has the same symbol on right (which looks like zero) and the same pencil marking on left side. There is also name of some company which I cannot read due to Low-resolution. I can read (c) AMERICAN -something- (2 missing words), CLEVELAND, USA, -something- (1 word).
