When I saw a receipt of an e-commerce, I found a sentence "Exclusions apply."
"Apply your 20-character promote code to receive this discount. Exclusions apply. See details at xxxxxxxx.com. Expires MM/DD/YY" on a receipt of an e-commerce.
What does the phrase mean? Particularly, I do not understand what "Exclusions" means in this sentence. Could you give me some concrete examples of "Exclusions"?