I'll just quote IB (like you did):
What does Payment in Lieu refer to?
Overview:
A Payment in Lieu, or Pil, typically refers to a cash debit or credit made to an account in recognition of a stock dividend. A Pil in the form of a debit will be made when an account is holding a short position in a stock on its ex-dividend date. This debit occurs as the lender of the shares which facilitated the short sale remains entitled to all dividends paid throughout the duration of the loan period.
Conversely, a Pil in the form of a credit is made when a long stock position in an account has been loaned out on its ex-dividend date. Account holders should note that shares which are held long and which are the subject of a margin lien may be eligible to be loaned by the broker. In this situation the credit originates from payment by the borrower of the shares rather than from a dividend by the share issuer. U.S. taxpayers who are recipients of Pil credits should discuss the tax implications of Pils and non-qualified dividends with their tax adviser.
https://ibkr.info/node/42
I highlighted the most relevant text. This seems to have nothing to do with the SYEP.
What does Payment in Lieu refer to?
Overview:
A Payment in Lieu, or Pil, typically refers to a cash debit or credit made to an account in recognition of a stock dividend. A Pil in the form of a debit will be made when an account is holding a short position in a stock on its ex-dividend date. This debit occurs as the lender of the shares which facilitated the short sale remains entitled to all dividends paid throughout the duration of the loan period.
Conversely, a Pil in the form of a credit is made when a long stock position in an account has been loaned out on its ex-dividend date. Account holders should note that shares which are held long and which are the subject of a margin lien may be eligible to be loaned by the broker. In this situation the credit originates from payment by the borrower of the shares rather than from a dividend by the share issuer. U.S. taxpayers who are recipients of Pil credits should discuss the tax implications of Pils and non-qualified dividends with their tax adviser.
https://ibkr.info/node/42
I highlighted the most relevant text. This seems to have nothing to do with the SYEP.