Using yaml folded style. The indention in each line will be ignored. A line break will be inserted at the end.
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.http://symfony.com/doc/current/components/yaml/yaml_format.html
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.In either case, each line break is replaced by a space.
There are other control tools available as well (for controlling indentation for example).