I could never figure this out

If you are offside and I score a TD....I take the TD and decline the penalty

If you are offside and I score a 2 point convert.....I take the 2 points and get 5 yards on the kickoff?

Why do I get the play and the penalty yardage on a minor penalty for one and not the other?

Converts are special. Non offending team gets the option of both on successful converts. Same in amateur.

I think I have seen it announced as declined at times but I'm not sure....I cant find anything in the rule book on it

And why should they be special?

According to the rulebook, only major fouls are applied to the subsequent kickoff. At least that's how I read it.

RULE 8 – APPLICATION OF PENALTIES
SECTION 5 – FOUL ON CONVERT
Article 1
If a foul is committed during a convert attempt prior to the ball being snapped or during Team A’s initial attempt to score a convert, the following shall apply:

(a) If either team commits a foul (except a Major Foul or Defensive Offside – see item (b) below) the non-offending team may elect to have the penalty applied from PLS and repeat the convert attempt, or accept the play as it terminated,

(b) If the foul is a Major Foul or Defensive Offside, the non-offending team may elect to have the penalties applied

(i) from PLS and repeat the convert attempt,

(ii) accept the play as it terminated and apply the penalties on the subsequent kickoff, or

(iii) repeat the convert from PLS and apply the penalties on the subsequent kickoff if the penalties occurred prior to the snap of the ball. If both a Major Foul and Defensive Offside are committed by Team B, the penalties may not be split between a re-try of the convert and the subsequent kickoff. They must both be applied from the same point of application,

Rule 3, Section 2, Article 5 (1b) of amateur rule book....sorry, don't have current CFL rule book. Infraction by team B on successful convert, team A has option to accept point and apply yardage on k/o.

"Why are they special?" Sorry, they just are.

That is what I have always thought....And what you posted only seems to apply if the convert is missed yet in todays game the convert was good and the offside was applied to the kickoff

If you want one

The current rulebook contains the following:

NOTE: Penalties that occur on convert attempts shall be applied according to Rule 8, Section 5.
And that rule states that only major fouls are applied on the following kickoff when the score is made.

Not sure, but I think this applies to all scoring plays. I could be wrong about that.

It uses the term "convert attempt", not "unsuccessful convert attempt" as it does in Article 2, so I'm assuming it applies to either successful or unsuccessful attempts.

Can't say why the offside penalty yards were applied on the kickoff. Doesn't seem to be in the rules (by my reading).

Wrong link. That's the Guide and Record Book. Here's the rulebook. It's on the CFL website, but there's no link that I can find. And not sure why, but there seems to be two copies back-to-back.

2017 CFL Rulebook

Yeah it was the wrong link sorry

Actually major fouls apply to all plays
For roughing the passer or horse collar tackle...you get yards gained plus the penalty yards

For offside, procedure or illegally down field....you get the play or the yardage, not both

Doh. I knew that. :-[