Why do some Castsequences have the location of spell in the talent tree?

I am really loving GSE. Already I am modifying different sequences for my style and level of play. One question, I noticed in a few places where the “Talent Tree Location” of a spell is called; example:
/castsequence [talent:1/2] Execution Sentence, Judgment
/cast [talent:4/1] Blade of Justice;[talent:4/2] Blade of Wrath; [talent:4/3] Divine Hammer

Can someone help me understand why the “talent” block is added, and in these situations are they like mini-step sequences within the larger overall sequence?

FYI the code comes from

Sequences['RetSingle'] = {
specID = 70,
author = "Ðarkramz",
helpTxt = "Talents: 1/2, 1/2, ?, 2, 1, 1/2, 1/2",
StepFunction = GSStaticPriority,
PreMacro = [[
/targetenemy [noharm][dead]
	"/cast Wake of Ashes",
	'/castsequence [talent:1/2] Execution Sentence, Judgment',
	'/cast [talent:4/1] Blade of Justice;[talent:4/2] Blade of Wrath; [talent:4/3] Divine Hammer',
	'/cast [talent:2/2] Zeal',
	"/castsequence Judgment, Templar's Verdict, Templar's Verdict",
	"/cast Templar's Verdict",
	'/cast Crusader Strike',
PostMacro = [[
/cast Wake of Ashes

That’s so when you switch Talents there’s no need to change or use another macro. The macro will fire off no matter what Talent has been picked.

It is a macro condition. If the condition isnt met (you dont have the referenced talent) then nothing happens there it moves on.

Hi MysticalNyte and Leper Messiah, thanks for the replies…
So as per the two of your explanations, I think I understand the following:
ex: '/castsequence [talent:1/2] Execution Sentence, Judgment',

  • let’s say I chose talent 1/3, since that isn’t what is specified in my macro (and thus I don’t have the talent of Execution Sentence, it would still cast Judgement and then go to the next line of ‘/cast [talent:4/1] Blade of Justice;[talent:4/2] Blade of Wrath; [talent:4/3] Divine Hammer’, which would only trigger on the talent I had chosen.
  • however if I had chosen talent 1/2, it would cast Execution Sentence and then Judgement before moving to the next line? Or will it only cast Execution Sentence and then move to whatever was chosen on the next line?

if I only called the talent by name, wouldn’t GS-E simply bypass that command and then go to the next, or is this a way of keeping it from “skipping” a conditional statement within a line… IE:

   talent 4/1 is available then cast
       cast Judgement
   cast judgement