In the world of Escorts and Spa/Studios, L2 is also known as Level 2, or a blow job
In the world of Escorts and Spa/Studios, L1 is shorthand for "Level 1" - or a hand job.
No, L7 is advanced Mouth to cock resuscitation with DT in the 69 position. If you are certified, that mean "advanced" swallowing as well. SNL is certified.