Period (.)

Use to end declarative or imperative sentences and in some abbreviations.

Use only one space after the period at the end of a sentence.

Don't use end punctuation in headlines, headings, subheadings, UI affordance labels, or list items that are not complete sentences.

Do

In the widget you can edit:
  • Numbers
  • Letters
  • Other characters
In the widget you can:
  • Edit numbers.
  • Edit letters.
  • Edit other characters.
Note The first list would be preferred for readability.