The letters are simply the codes that you shouldn’t concern yourself with too much. In your example, the letters probably stand for (top to bottom)
Whitetail
Supplemental,
Strathcona
Whitetail,
General
Deer,
Foothills
Deer (first letters of the codes highlighted). For elk, you would have GX, where G is for General and X is for elk. What these are good for, you’d have to look in the regulations for any particular zone you want to hunt in.
As for your question for elk, here is an example from the regs based on the 500s:
The black square indicates that this is a season for the “special” licenses only, in other words draws. Where there is no black square, those seasons you can hunt those species with a “general” or “over-the-counter” license. So for example, in WMU 509, the 6-point rule applies for antlered elk, which you can hunt with a bow (unless permitted to hunt with a crossbow, but you probably do not qualify) - because those seasons are in the archery season column - with a general license (and a bow hunting permit) from September 1 to October 31, but need to be drawn for hunting an antlered elk there through November with any legal firearm, as well as a bow (still need a bow permit if hunting with a bow). The same dates apply for hunting an antlerless elk with a bow in the same WMU under the general license, but one needs a draw to hunt the same antlerless elk there from November 1 to December 20 with any legal firearm or a bow.
Now look at your 302 example for antlered elk:
As you can see, there is no draw for antlered elk in the 300s, including WMU 302, because there are no black squares indicating a draw. So in WMU 302, you can hunt elk with a general license using a bow from September 1 to October 24 (need a bow hunting permit as well) and with a any legal firearm from October 25 to November 30.
Now look at the antlerless elk in the same WMU:
They are all on draw for the general (or “gun”) season due to the little black squares in front of the dates. And that is generally the case in Alberta for antlerless elk. However, in some management units, you can hunt them under a general license during the archery season. Such is the case in WMU 302 where there is an archery season for antlerless elk from September 1 to October 24.
It may seem complicated, but you will get a hang of it pretty quickly.
And good luck! If you have questions, don’t be shy to ask, I am sure someone will answer. As the other poster noted, however, read the regs. It is a
must and there isn’t that much to read. Then read again and make sure you understand what you are reading. Don’t read Alberta Relm, but either download or get the actual paper booklet at Canadian Tire or elsewhere (have one in the washroom, for example). I know some things appear to be overly complex, but it is just an illusion, really. Once you get it, you are good to go. Sometimes experienced hunters here ask questions that may seem complex to some and quite silly to others. On the next question, things very well could be reversed in regards to those who think it is complex and those who think it is silly. And I will repeat, reading the regulations is key.
Hope this helps.