Use of Jokers in Exposures (Article ID 48)
Abstract: Yes, a player may use as many jokers as need to call (claim) a tile as needed to complete a pung, kong, quint, or sextet. A player should use Jokers wisely and consider factors such as but not limited to being in the beginning, middle, or end game. Using all of one’s Jokers to call for an exposure early in the game might leave you unable to call other needed tiles as they are discarded. However, if your use of all of your Jokers puts you on call during the game, then doing so would make sense.
Another thing to consider is whether to use all of your Jokers in an exposure in the end game even if it puts you on call. In this case, consider whether all the symbol tiles have been discarded. If they have not, you are leaving a joker exchange available to another player, which may give them mah jongg.
The answer provided is from Mah Jongg Made Easy and is the closest to the question which references jokers used after claiming a discarded tile.
Question from a player: Can I use jokers to claim a discard to make an exposure?
Answer from the NMJL: “Jokers may be used to replace any tile (Numeral, Wind, Dragon or Flower) , in a Pung, Kong, Quint or Sextet only.”
Source: Mah Jongg Made Easy (2020 page 7 para. 1, page 22 #2, page 23 #10, page 30, para. 6)
Other answers from the NMJL:
“A player may use her jokers and call a symbol tile, but it is a waste unless this “call and exposure” sets the hand for mah jongg.”
Source for other answers: National Mah Jongg League Bulletin Q&A (1967 page 5, 1968 page 5) https://www.nationalmahjonggleague.org