Here's a breakdown:
* WL: This stands for "waitlist." It means the applicant has not been offered a place immediately but is placed on a list of potential students.
* LJS: This likely refers to the London Joint School, a group of independent schools in London, England.
Therefore, "1 WL on LJS" signifies that the applicant is the first person on the waitlist for the London Joint School.
Important Note: This interpretation is based on common usage. To be certain, it's best to confirm the specific context where you encountered this phrase.