trying to define "liberal"

How could one define "liberal"-- as opposed to someone on the Left, a progressive, or various posers among self-styled liberals? (Here's an essay on this topic from me a decade ago (!) to define liberal with an emphasis on different types of self-styled liberals.) The exercise is difficult and my efforts would be debatable. But it's an interesting exercise. Let me give it a try (and then stick it in my blog!).

"Liberal" would include an emphasis on:

1.) freedom and choice (with its implied connections to the importance/usefulness of knowledge and education),

2.) equality of opportunity (at least rule of law and equality before the law-- but could extend into questions about access to resources and redistribution to allow more choice);

3.) tolerance socially and in terms of legislation (allowing and extending freedom to others);

4.) humility vs. self-righteousness in style (given their understanding about limits on knowledge and acknowledging the validity of different preferences); and

5.) openness to change and experimentation, esp. socially (see: tolerance) and politically (avoid limiting freedom; look to expand freedom; state and local is more promising than federal).

This is along the lines of what is often called a "classical liberal" today. Anything to add to my list here?

Some prominent, ironic, nasty contemporary examples of illiberal positions held by self-styled liberals: insisting on an overly-expensive govt monopoly in education over the poor (instead of giving them resources so they can exercise choice-- as the GI Bill, Food Stamps, etc.); shouting down speakers at universities instead of engaging in dialogue; insisting on federal approaches to health care or how to handle the gun/violence problems in schools.