I am importing a text file with Swedish letters (å, ä, ö).
A. If I use ReadList["sv_JSPFirefox.txt"], it imports the file nicely but then I cannot use a command line like:
dict2 = Select[dict1, Not@StringContainsQ[#, Alternatives @@ rejectlist] &] The error code is:
StringContainsQ::strse: String or list of strings expected at position 1 in StringContainsQ[Aapua,.|0|1|2|3|4|5|6|7|8|9|{A,B,C,D,E,F,G,H, I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z}|Å|Ä|Ö]. >> Two screen dumps show the problem better:

B. If I use: ReadList["sv_JSPFirefox.txt, Word] it imports the file but those characters are a mess; but at least I can use the command above and proceed; but commands (search, etc) including these characters do work properly.
I have tried to add "UTF8", "UTF-8","Unicode", "Lines" and other options but nothing seems to help. Any pointer in the right direction would be greatly appreciated. Thank you for your time!
20160306 Edit. @C.E. I made a sample file and a very small file called "shrimpsandwich.txt". This is enough because this is a word in Swedish that contains all three letters, "räksmörgås". You might have heard of smörgåsbord.
Sample files: A small sample file is displayed in the screen dump above.

ReadList, but I can't reproduce your problem. Can you provide a file - does not have to be your entire file, it can be a smaller one - as well as a definition forrejectlistso that we can reproduce the problem? Also have you tried usingImport? (e.g.StringSplit@Import[file]) $\endgroup$DictionaryLookup[{"Swedish", Repeated[___ ~~ "å" | "ä" | "ö" ~~ ___, {3, Infinity}]}]clearly shows that räksmörgås is not the only word in Swedish with å, ä and ö in it. $\endgroup$dict3 = Select[dict2, Not@StringContainsQ[#, Alternatives @@ idagThrowAway] &]$\endgroup$dict1 = ToString /@ ReadList["sv_JSPFirefox.txt"]it all works! Awesome! Now, the question arises in my mind: What was the problem, and what is different in this solution? If you have some time, please do explain. $\endgroup$