Advanced search gives non-100 scores to exact name matches.

E.g. http://musicbrainz.org/search?query=republica&type=artist&advanced=1 gives a score of 100 to artist named República, and Republica gets 92.
Non-advanced search (http://musicbrainz.org/search?query=republica&type=artist&limit=25) gives both a score of 100.

See also discussion from here on: http://chatlogs.musicbrainz.org/musicbrainz/2011/2011-12/2011-12-29.html#T18-51-23-548524

More examples:

http://musicbrainz.org/search?query=kino&type=artist&limit=25&advanced=1 — British Kino gets a 100, German Kino 92, Russian Kino (Кино) 62.
http://musicbrainz.org/search?query=kino&type=artist&limit=25 — British and German Kino both 100, Кино 95.

http://musicbrainz.org/search?query=bruno&type=artist&limit=25&advanced=1 — Downtempo DJ gets a 100, Estonian and uncommented both get 91, DR TV artist gets 73 (probably because of the sortname).
http://musicbrainz.org/search?query=bruno&type=artist&limit=25 — all four get a 100.

http://musicbrainz.org/search?query=fix&type=artist&limit=25&advanced=1 — Dutch 100, Estonian 92.
http://musicbrainz.org/search?query=fix&type=artist&limit=25 — both 100.

http://musicbrainz.org/search?query=him&type=artist&limit=25&advanced=1 — Finnish HIM 100, and HiM, HIM (Hiromasa Ijichi Melodies), H.I.M and H.I.M. all 92.
http://musicbrainz.org/search?query=him&type=artist&limit=25 — all five get a 100.

http://musicbrainz.org/search?query=mass&type=artist&limit=25&advanced=1 — only Mass the member of B.O.S.S. gets 100, all other Masses (and both M.A.S.S.'s) get 92.
http://musicbrainz.org/search?query=mass&type=artist&limit=25 — all Masses and both M.A.S.S.'s get a 100.

http://musicbrainz.org/search?query=nirvana&type=artist&limit=25&advanced=1 — "the" Nirvana gets 100, Finnish and UK bands get 92, El Nirvana 64, Νιρβάνα (sortname Nirvana) 36.
http://musicbrainz.org/search?query=nirvana&type=artist&limit=25 — all Nirvanas get 100, Νιρβάνα 98, El Nirvana 62.

http://musicbrainz.org/search?query=rem&type=artist&limit=25&advanced=1 — R.E.M. 100, both Rems 92.
http://musicbrainz.org/search?query=rem&type=artist&limit=25 — all three get 100.

http://musicbrainz.org/search?query=tyr&type=artist&limit=25&advanced=1 — Týr 100, both Tyrs 92.
http://musicbrainz.org/search?query=tyr&type=artist&limit=25 — all three get 100.

http://musicbrainz.org/search?query=troll&type=artist&limit=25&advanced=1 — most Trolls get 100, the Canadian guitarist gets 79.
http://musicbrainz.org/search?query=troll&type=artist&limit=25 — he, too, gets a 100.

Counter-examples (i.e. okay either way):

http://musicbrainz.org/search?query=akos&type=artist&limit=25&advanced=1 and http://musicbrainz.org/search?query=akos&type=artist&limit=25 — either way, Ákos and Akos both get a 100.

http://musicbrainz.org/search?query=dago&type=artist&limit=25&advanced=1 and http://musicbrainz.org/search?query=dago&type=artist&limit=25 — either way, Dagö, Dago and D.A.G.O. all get a 100.

http://musicbrainz.org/search?query=muse&type=artist&limit=25&advanced=1 and http://musicbrainz.org/search?query=muse&type=artist&limit=25 — either way, all Muses get a 100.

Weird either way:

http://musicbrainz.org/search?query=oobik&type=artist&limit=25&advanced=1 / http://musicbrainz.org/search?query=oobik&type=artist&limit=25 — Röövel Ööbik 100, Oobik & The Pucks 85/80. Shouldn't the latter score higher in theory?

http://musicbrainz.org/search?query=sinead&type=artist&limit=25&advanced=1 / http://musicbrainz.org/search?query=sinead&type=artist&limit=25 — no-one should get 100 since there's no artist named simply Sinead/Sinéad/Sínèäd/Šïńęâð in the db. And the differing scores are weird as well.

http://musicbrainz.org/search?query=spinal&type=artist&limit=25&advanced=1 / http://musicbrainz.org/search?query=spinal&type=artist&limit=25 — no-one should get 100 here either.