Rigid vs flexible Bridge pattern

In a software design course, we've been given a term that I'm inclined to call "mysterious" since no internet search can reveal it. The term waas given in a language native to my place, but the English translation for it would as follows: "rigid" or "hard" Bridge pattern vs the "soft" or "flexible" Bridge pattern. Gamma obviously fails to describe this.

• What could this mean? I think experienced architects should be familiar with the two main different types of bridges, even if they call that differently.
• Is there a book on patterns more realistic and containing more experience that the Gamma et al. reference book?

The last question can be deemed opinion based according to the rules, feel free to remove it, but leave the Bridge question intact. Thank you for understanding.