Key: >
  This is a very long sentence
  that spans several lines in the YAML
  but which will be rendered as a string
  with only a single carriage return appended to the end.
  
# You can use the "block chomping indicator" to eliminate the trailing line break, as follows:

Key: >-
  This is a very long sentence
  that spans several lines in the YAML
  but which will be rendered as a string
  with NO carriage returns.