Common generic bones ( for player models and some HL2 models ):

• ValveBiped.Bip01_Head1
• ValveBiped.Bip01_Spine
• ValveBiped.Anim_Attachment_RH

Common hand bones (left hand equivalents also available, replace R with L)

• ValveBiped.Bip01_R_Hand
• ValveBiped.Bip01_R_Forearm
• ValveBiped.Bip01_R_Foot
• ValveBiped.Bip01_R_Thigh
• ValveBiped.Bip01_R_Calf
• ValveBiped.Bip01_R_Shoulder
• ValveBiped.Bip01_R_Elbow