[Amps] YU209

[Charles Bibb - K5ZK]

What is the difference between an 8877 / 3CX1500A7 / YU209?

I'm told that the YU209 is a "commercial version" of the 8877, but 
what makes it different?

Are the data sheets identical?  If so, can someone point me to 
one?  I've not had any luck locating one on my own.  If the data 
sheet for the YU209 and 8877 are exactly the same, what makes a tube 
a "commercial" version?

73,
Charles - K5ZK