To introduce a list, the punctuation mark that should be used is a colon (:). A colon is commonly used to indicate that what follows is a list of items related to the preceding information.
For example:
- The following ingredients are needed for the recipe: flour, sugar, eggs, and milk.
In this sentence, the colon introduces the list of ingredients needed for the recipe. It helps to clearly separate the introductory information from the list that follows.
Using a colon to introduce a list helps in making the text more organized and easier to read for the reader. It signals that a list is coming up, preparing the reader to expect a series of items.