I'm currently using google chrome to inspect the elements of a bigger project I am working on and noticed that it gives very neat hints (e.g. striking through properties that are later overwritten). It also gives the hint that a property is invalid with a yellow exclamation mark. Is this information browser specific and it is only not valid in google chrome or can I assume that this property will not work anywhere? (of course I could look up every property for which I get this warning, but if I knew definetely these were unnecessary I could get rid of them without much hassle)
Striking through properties that are overwritten should generally reflect general CSS rules, i.e. be browser-independent. But the browser’s code for that might be buggy. Moreover, a potentially overriding rule might use a nonstandard value for a property, and then it would depend on browser whether it really overrides.
Indicating properties as “invalid” in browser tools should be taken just as saying that the browser does not recognize (support) the property. So it would be very much browser-dependent. It may also depend on browser version.