How can one enable a website for better searching by search engines?

Keywords

oai-pmh
google sitemap
dublin core
eprints.org
oai registries
mod_oai
oai gateway service

References

SEARCH ENGINE COVERAGE OF THE OAI-PMH CORPUS - Frank McCown, Xiaoming Liu, Michael L. Nelson, Mohammad Zubair

OAI protocol

Open archives

Googles sitemap protocol