Follow up on #350.

README.md

@@ -93,7 +93,6 @@ Notes:
       cat hosts | xargs -I{} ssh root@{} hostname
 ```
 
-- Prefer the `-0` or `-print0` options to enable null characters to delimit filenames. This better supports filenames with whitespace.Example : `locate -0 pattern | xargs -0 ls -al` or `find / -print0 -type d | xargs -0 ls -al`. To iterate on filenames containing whitespace in a for loop, set your IFS to only '\n' using `IFS=$'\n'`. Always surround your bash variables with `"`.
 
 - `pstree -p` is a helpful display of the process tree.
 
@@ -111,6 +110,8 @@ Notes:
 
 - Use `alias` to create shortcuts for commonly used commands. For example, `alias ll='ls -latr'` creates a new alias `ll`.
 
+- Understand that care is needed when variables and filenames include whitespace. Surround your Bash variables with quotes, e.g. `"$FOO"`. Prefer the `-0` or `-print0` options to enable null characters to delimit filenames, e.g. `locate -0 pattern | xargs -0 ls -al` or `find / -print0 -type d | xargs -0 ls -al`. To iterate on filenames containing whitespace in a for loop, set your IFS to to be a newline only using `IFS=$'\n'`.
+
 - In Bash scripts, use `set -x` (or the variant `set -v`, which logs raw input, including unexpanded variables and comments) for debugging output. Use strict modes unless you have a good reason not to: Use `set -e` to abort on errors (nonzero exit code). Use `set -u` to detect unset variable usages. Consider `set -o pipefail` too, to on errors within pipes, too (though read up on it more if you do, as this topic is a bit subtle). For more involved scripts, also use `trap` on EXIT or ERR. A useful habit is to start a script like this, which will make it detect and abort on common errors and print a message:
 ```bash
       set -euo pipefail