Correct, however i didn't go into the datasheets to see if some obscure parameter was slightly better or not.
You will find that certain companies will sometimes stick their own prefix in front of a generic device sometimes not, like on 1Nxxxx diodes or 2Nxxxx, 2scxxxx ,2saxxxx etc transistors. Sometimes on trannys they will leave off the first two letters as with 2sc945 may show as a c945. or its compliment 2sa733 will show only a733. Over time you learn the patterns and sometimes you need to be a Sherlock Holmes.
You can for fun, do a search from the website I linked to for HA17 and see if you can decipher Hitachi's markings. That's assuming they have a system or keep to it. Also search for HA1, this may enlightened you to a pattern. Alternatively, you could search for Hitachi but you may end up with a bazilion hits.
Cheers