The Sherman classification is a classification based upon the situation of an ACL (anterior cruciate ligament) tear.

Sherman Type I - really an avulsion from the bone at the top of the notch rather than a tear through the substance of the ACL.

Sherman Type II - a tear through the substance of the ACL in the upper 1/3 of the ligament.

Sherman Type III.
[Type IV has the tear right in the middle of the ligament.]
The relevance of the Sherman classification for ACL tears
The situation of the anterior cruciate ligament tear is particularly relevant in injuries of children. Type I tears (avulsions) are particularly amenable to repair as opposed to reconstruction. Reconstruction may be problematic in children where the bones are still growing as the surgeon will likely try to avoid any injury to the growth plate when making the tunnels for the new ligament.
CLINICAL PUBLICATIONS
The Location of Anterior Cruciate Ligament Tears: A Prevalence Study Using Magnetic Resonance Imaging. Jvan der List JP, Douglas N. Mintz DN and DiFelice GS. Orthop J Sports Med. 2017 Jun; 5(6): 2325967117709966.
2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries Ardern C et al. Knee Surg Sports Traumatol Arthrosc. 2018; 26(4): 989–1010.