From fe6c6a7677b6fd3543d05f367480998271dcef38 Mon Sep 17 00:00:00 2001
From: Dylan Araps <dylan.araps@gmail.com>
Date: Thu, 19 Sep 2019 12:01:15 +0300
Subject: [PATCH] docs: update

---
 README.md | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/README.md b/README.md
index 6d4052c..7c99062 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,8 @@ A collection of pure POSIX `sh` alternatives to external processes
 * [TRAPS](#traps)
     * [Do something on script exit](#do-something-on-script-exit)
     * [Ignore terminal interrupt (CTRL+C, SIGINT)](#ignore-terminal-interrupt-ctrlc-sigint)
+* [OBSOLETE SYNTAX](#obsolete-syntax)
+    * [Command Substitution](#command-substitution)
 
 <!-- vim-markdown-toc -->
 
@@ -546,3 +548,20 @@ trap clean_up EXIT
 ```shell
 trap '' INT
 ```
+
+# OBSOLETE SYNTAX
+
+## Command Substitution
+
+Use `$()` instead of `` ` ` ``.
+
+```shell
+# Right.
+var="$(command)"
+
+# Wrong.
+var=`command`
+
+# $() can easily be nested whereas `` cannot.
+var="$(command "$(command)")"
+```