Introduction
This is the second in my series of caches meant to teach people some ways to solve puzzle caches. Please read the information above the line in Puzzlers Lesson 1: Alphabets. That lesson taught you one way of translating letters to coordinates, and this one will show you some more that are less common.
Computer Keyboard
The key to one common way is at (or near) your fingers right now. Look down at your computer keyboard. Notice how each row of keys is slightly offset from each other. Going up the keyboard (away from the space bar) each row is slightly more than ⅓ of a key to the left of the row below it.
If you follow each of these slanted columns to the top (furthest from the space bar) you'll see a row of numbers, with some other symbols in the shifted position. (We won't deal with these at this time, but some puzzles have used these symbols.) So, using this encoding 1=QAZ, 2=WSX, etc. And someone could use the other diagonal, but that doesn't work for all of the digits.
So the posted coordinates using this encoding could be RAPT CUD ZAZ BIRFI.
Telephone Keypad
Another keyboard that you have near you is on that computer you often keep in your pocket, purse or backpack. It's your telephone, if you haven't guessed already. There are even other variants of telephone keypads (section 5.4), but they won't be used here.
There are no letters on the normal (ITU E.161) telephone keypad for the digits 0 and 1. Some puzzles are done with no substitutions for 0 and 1; that is, no letters are substituted for them. However, not everyone will do this. The old telephone dials did not use the letters Q or Z, so these could be used for 0 or 1, but there would be no standardized way to do this. You may just have to guess. I'll use Q=1 and Z=0 in this puzzle. (Another way to encode 0 will be discussed in a future lesson.)
So the posted coordinates using this encoding could be GQ ZK ERD QQQ JU HIT.
Strokes
Another encoding is to count the number of strokes required to draw the letter, so 1=CIOSU, 2=DGJLPQTVXY, 3=ABFHIKNRZ and 4=EMW. Notice that 'I' is 1 or 3 depending on how it is drawn, but I prefer drawing it with the cap and foundation so I would count it as 3. Some others are also ambiguous. Again, if someone uses this encoding then there should be some way to figure out how to count strokes. Note that there aren't any large values, so 8 could be expressed as E+W. Note: This is an obscure enough encoding that whomever makes a puzzle like this should definitely give some sort of hint that this is what they're doing.
So the posted coordinates using this encoding could be MO X-YC+W HN+EA COS A+DW+E WME+W.
Word Games
And yet another encoding is to use the Scrabble or Words With Friends values for each letter tile, or even the number of letters in a standard game. This is another encoding that is obscure enough that a hint should be given, such as using "scramble" because it is a word similar to "Scrabble".
So the posted coordinates using this encoding could be FZKBJ-AP AEIKJVWX.
Puzzle
Now, for the twist and puzzle on this one: The puzzle is encoded using the computer keyboard, telephone keypad and Scrabble letter values, but not in that order. However, the same order will be used throughout the 15 digits of the puzzle. So, once you find out which order is used for the first three, that same order will be repeated for the rest of the puzzle. So, AB CA.BCA BCA BC.ABC, where A is always the same encoding, etc.
RAZGGXXOQQKVCXT
You can validate your puzzle solution with certitude.
Congratulations to UsLaynes for being first-to-find on this cache, as well as the first in this series.