Investing layer of deep cervical fascia

The Investing layer of deep cervical fascia is the most superficial part of the deep cervical fascia, and it encloses the whole neck.
Attachments.
It surrounds the neck like a collar, it splits around the sternocleidomastoid muscle and the trapezius muscle. It is attached as;
Tracings.
 - It splits at lower border of submandibular gland into superficial and deep layers;which attach to lower body of body of mandible and mylohyoid line of mandible
 - It splits at lower pole of parotid gland into superficial and deep layers; superficial layer attaches to zygomatic arch and forms parotido-masseteric fascia after blending with masseter, deep layer attaches to tympanic plate and styloid process forming the stylomandibular ligament
Existence.
It is considered by some sources to be incomplete or nonexistent.