Turbine Engine Questions: Squealer Tips & Classified Weights?

[PA32]

I recently saw the terms "Squealer Tips" and "Classified Weights" in a text about turbine blades in an article on the Pratt & Whitney PT6A turbo-prop engine. Can anyone explain what is meant by these two terms? What are they and what do they "do"?

 

[Pkruse]

I would understand that to mean they got information from people with access to unpublished information, but without the authority or permission to release it.

 

[AlephZero]

Google will tell you what a squealer tip is. This must be a US term., I never heard of it on my side of the Atlantic. The idea seems to be a leftover from steam turbine design practice.

A classified weight is presumably the weight of something that is classified (i.e commercially confidential, or a military secret) information.