While editing and updating for registered errata, I found there are many(?) span element with class=index and 8 character id which are mostly surrounding links to references etc. These are only in Japanese version of old format but not in English version. Also there is no internal link for these using id.
Are these used for document, or just leftovers from some editing software (or conversion software)?

Just filing as memo (or question for next F2F), not adding errata label.