Pizza Dough Yeast vs. Bread Dough Yeast?

[Hetron]

What's the difference between pizza dough yeast and bread dough yeast. Fleischman pizza dough yeast package says don't use for bread baking. 

[Davescprktl]

I Googled it and found out that it can't be used for bread because of dough relaxers added to the yeast.
I glad you brought this up.  I need to try this stuff.