This is a percent-encoded string.
The decoded version of the string is ìåëèññà
.
Each character of the string has a percent-encoded representation, so the first character ì
is encoded to %EC
, and so on.
The percent-encoding of a string can be different depending on the character set of the string. In this case, the string is in ISO-8859-1, where ì
is represented as 0xEC
, hence the percent-encoding %EC
. However, in UTF-8 it is represented as 0xC3 0xAC
, so the percent-encoded version of the UTF-8 string would start with %C3%AC
.