I thought this was quite interesting. I was looking at the halloween card and the way he spelled Paul Avery’s name. He underlined the LAV part and there are 3 lines at the top of the symbol. He added an L to Avery’s surname as well which makes ERLY after the line and there are four dots. So if you use the first three letters of his name and the LAV he underlined then the apply the last four letters to the dots you get something like this.

If you look on the left it says PAL and underneath Z, so your secret pal Z or zodiac.