Yes it is Swedish Æ, Ø are used in Danish and Norwegian.
I suspect the to upper-case function don't work correctly ether but few caches starts with lower-case letters
The only one i found was älgen
http://coord.info/GC2BDM8
But when i tested the checker for that cache wit a user with few find Rottafia i noticed that thee was no no listing of qualifying caches when the requirement is not met.The missing row is empty.
I would like if there was a output of ok find even if i fail. Because if you test is and fail and you see caches and just not a number it feel that you have done something and I would be more inspired to complete the challenge. An if you are logging caches to meat the requirement it is nice to be able to look and see new caches added.
My checkers often outputs a best result if you fail because it is fun to se when you almost did it
In this case incorrect ok find can also be detected
I tested som of the finds of the cache and only found one error
j2dad
GC5M165 προειδοποίηση 2015-02-13
and had logged with ווארענונג - Varenung - CITO that starts with a Hebrew ג(Gimel) or a ו(Vav) depending of how left right test are interpreted
But i suspect that if all letters used in Spanish (when the cache in in Texas) is included there will not be a big problem. in the wiki page i could find that a keyboard should have
á, é, í, ó, ú, ñ, Ñ, ü, Ü, ¿, ¡. Á, É, Í, Ó, and Ú
Some of the upper case are missing in your checker and should be added