why do some kanji have multiple stroke counts?


A few years ago, I came across the issue of one kanji having multiple stroke
counts. Now, I need to review this:  
牙 = (4 or 5 strokes)  
瓜 = (5 or 6 strokes)  
邑 = (6 or 7 strokes)  
....

If native speakers don't know about this ambiguity, then I'll just ignore it.
But, if it is something to be aware of, can someone please check these
assertions?  
(1) Depending on the era, some kanji's stroke counts changed. One stroke count
is considered correct in modern Japan, while the other is just a historical
footnote.  
(2) Counter to the trend of simplifying kanji, the modern writings have the
greater number of strokes.

Any more information would be welcomed. thanks.




There are currently 1,006 kanji that are taught in elementary schools and
those are named 教育漢字. It is only these 1,006 kanji that are given "official"
stroke counts by 文部科学省, Ministry of Education, Culture, Sports, Science and
Technology.

Strange as it may seem, the other kanji simply do not have official stroke
counts. What that means is that it is left to the discretion of the individual
publisher and dictionary author.

The 1,006 kanji are listed
[here](http://ja.wikipedia.org/wiki/%E5%AD%A6%E5%B9%B4%E5%88%A5%E6%BC%A2%E5%AD%97%E9%85%8D%E5%BD%93%E8%A1%A8)
on Wikipedia.




There are currently 1,006 kanji that are taught in elementary schools and
those are named 教育漢字. It is only these 1,006 kanji that are given "official"
stroke counts by 文部科学省, Ministry of Education, Culture, Sports, Science and
Technology.

Strange as it may seem, the other kanji simply do not have official stroke
counts. What that means is that it is left to the discretion of the individual
publisher and dictionary author.

The 1,006 kanji are listed
[here](http://ja.wikipedia.org/wiki/%E5%AD%A6%E5%B9%B4%E5%88%A5%E6%BC%A2%E5%AD%97%E9%85%8D%E5%BD%93%E8%A1%A8)
on Wikipedia.

