Heredocs are used for multiline strings in [[POSIX Shell]]. The syntax is as follows: Example: ```shell cat <<EOF This content is passed to `cat`'s stdin EOF ``` Uncommonly used, but a number may be specified before the `<<` to control the input file descriptor. For example, `cat 2<<EOF ...` would send to `stderr`, though I don't *think* this would work as intended. If `<<-` is used instead of `<<`, leading `<tab>` characters are stripped from the contents of the doc. [Reference](https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_07_04)