In Oboe is it necessary to use the left pinky when playing F, D without a slur

1. When to use forked f oboe?
2. What is a Philadelphia D key?

When to use forked f oboe?

The Forked F is named for the fingering of the right hand, which does not use the middle finger. This F fingering is descended from the baroque oboe and inherits the difficulty of that note. This F is necessary to smoothly move between F and any note that requires use of the ring finger of the right hand.

What is a Philadelphia D key?

Philadelphia D Key ('high D' facilitator) - So-called because it was invented in Philadelphia. It's primary function is to improve the response of the high D. The key closes the ring isde the key that covers the E tone hole.