The following is an article name cut and paste from Wikipedia:
The Wikipedia pack fails to find the article. Replacing the “%26” with “&” fails as well and returns a “no article found …” error message. Copying and pasting the entire URL does returns an error message in which the “%26” is replaced with “&”.
https://en.wikipedia.org/wiki/J._S.Fry%26_Sons (also fails).
I have not tried all other encoded characters but it also fails on “%27” or the single apostrophe.
On a related note, I can view the following article in Wikipedia and copy the URL but the pack is unable to retrieve the article:
en…/wiki/Tcho takes you to a disambiguation page which links to the capitalized spelling.