May be short for Napoléon Coste, French guitarist and composer of the Romantic classical period. ('La Cachucha' caprice sur l'air espagnole for example or the Works for Guitar & Oboe CD).
http://en.wikipedia.org/wiki/Napol%C3%A9on_Coste

In some cases appears to be a link-up with an album series, Hotel Costes; see:
http://www.last.fm/music/New+Phunk+Theory/_/La+Neblina+Del+Verano

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