Records: https://github.com/janestreet/base/blob/master/src/avltree.m...
If statements: https://github.com/janestreet/base/blob/master/src/string.ml...
Lists: https://github.com/janestreet/base/blob/master/src/string.ml...
Function calls: https://github.com/janestreet/base/blob/master/src/string.ml...
Type definitions: https://github.com/janestreet/base/blob/master/src/array.ml#...
It's not always used, shorter snippets tend to be all on one line.