, 20111004 * Determine that normative RFC 2119 terms (MUST, SHOULD, MAY, etc.) are truly intended in all cases where capitalized. * Several passages could be made clearer. * Overall edit for scope. Portions are phrased as an introduction to the 0.1.3 RIFF container additions, rather than a holistic guide to WebP. * To wit, suggest s/[spec|specification]/guide/g . "Spec" can imply a standards track; in any case it's too formal for a work in progress.