The Uniform Resource Locator specification requires that some commonly used characters be converted into another form or in to a non-space character. This information only applies to the parameter section of a URL. You would only use the parameter section if you were returning a 'Location' header (eg: initiating a glimpse search from within the Form Processor). The most commonly used characters and their equivelents are:

NOTE: Do not escape the ampersands used to separate the parameters in the URL.

Character Original Escaped/converted
Slash / %2F
Space ' ' +
Tilde ~ %7E
Ampersand & %26
Question mark ? %3F
Equal Sign = %3D
Semicolon ; %3B