Hello,
While studying the IPQ I noticed something odd (at least in my eyes):

3.5 Deck/Decklist Problem:

Additional Remedy

(..) If the remaining deck has too few cards, add basic lands of the player’s choice to reach the minimum number.
This change may be reverted at a later point if replacements for lost cards are found.
3.8. Tournament Error — Marked Cards

Additional Remedy

(…) If the player is unable to find replacement cards, he or she may replace those cards with basic lands for the remainder of the tournament.
If he or she chooses to do so, the decklist is changed and cannot be reverted, even if replacements are found.

Why do we treat both situations the same up to one point (replacing by basic lands) and then treat them differently?
The Annotated IPG explains regarding the Marked Cards:
Due to the hassle and logistical issues with fetching decklists out, the change to a decklist cannot be reverted if, for example, replacement Huntmasters of the Fells are found later.

Obviously the same argument could be made for the Deck/Decklist Problem.

Best regards
Steve

Edited Steve Hatto (Aug. 27, 2015 05:44:06 PM)

It comes down to this:

If I lose my card and I cannot find a spare copy I will get a basic land instead.
If later I manage to find it ore trade for a new one I can replace it and the deck list will be corrected.

If I the same card can no longer be played because it has been marked and I cannot find a spare copy I will get a basic land instead.
If later I manage to find a new unmarked one I can’t replace it and I will be stuck with the basic land.

Can I refer you to this thread on the issue

Thx