Open a new window loading a page with German letters (Umlauts, Eszett, etc.) in its url (-++¥+p__n.html)

HTML 4.01 section B.2.1 Non-ASCII characters in URI attribute values says:

the following href value is illegal:

<A href="http://foo.org/Hskon">...</A>

We recommend that user agents adopt the following convention for handling non-ASCII characters in such cases:

1. Represent each character in UTF-8 (see [RFC2279]) as one or more bytes.
2. Escape these bytes with the URI escaping mechanism (i.e., by converting each byte to %HH, where HH is the hexadecimal notation of the byte value).

Same link as above but this time with the non-ASCII characters escaped: %D0%C3%C5%A5%D6%E3%DF%DC%FC.html