Basically a WikiName is just a username, but in Wiki format.
By that it means stick more than one capital letter in it somewhere. EG. Jesse isn't a WikiName, but JesSe is.
This comes from "CamelCase" use so that wherever your user name appears in the Wiki it becomes a link to your page in the Wiki, basically it saves you inputting the link with the name, all pages are named with a CamelCase name, its an idea to save time and make things easy...

Examples:
camelcase
CamelCase
CamelcasE
CAmelcase
CamelCasE
cAmelcase
cAmelCase
CamelCAse
Camelcase2
CamelCase3
CAmelcase4
camelCase5
camelcase6
Camel7case

Notice that some of those are interpreted as real CamelCase, and some are not.
Notice that all the different ones that are interpreted as real CamelCase all get automatically mapped to the one true existing CamelCase entry (this page). This is a very important feature! It means that we won't have a bunch of confusing pages with almost exactly the same names.
Notice that just putting two caps at the beginning is not enough -- there must be an initial cap, then some lower case, then at least one more cap!
Notice that numbers within or at the end of the word are processed as Caps, and trigger CamelCase mode.