嗅 #129 in 6th ed
Can this be written without the last stroke? (the “drop” in the dog kanji). In type and in dictionaries, this is written exactly as above. But in the Heisig book, the last stroke is emitted. Is this is big deal, and which way should I learn?

The one with the drop is the correct form, but unless you're doing kanken or something I hardly think it matters one way or the other.

I'm pretty sure that it's an error that the book is missing the last stroke.

I don't think it's an error because the Japanese government guidelines are still confusing on which form (or both) is correct.

The issue is that 臭 on the Joyo List is officially simplified to the form without the dot. There is no official pronouncement on how to write characters that are not on the Joyo list -- that is, whether you should write 嗅 with the dot or without it. Now in the recent revisions, 嗅 was added to the Joyo List but it's still not entirely clear whether it's OK to write it without the dot. Probably it's better to leave the dot there but it doesn't really matter that much.

Inny Jan Wrote:I'm pretty sure that it's an error that the book is missing the last stroke.

Or it could be Dr. Heisig's preference for 拡張新字体, as seen in the RTK supplement that was put out for the 5th edition.