diff --git a/docs/common/footer.php b/docs/common/footer.php
index c252b82..5cf3d81 100755
--- a/docs/common/footer.php
+++ b/docs/common/footer.php
@@ -15,6 +15,22 @@
 						" by php/".phpversion()." ".$_SERVER["SERVER_SOFTWARE"];
 					?>
 				</p>
+				<p>
+					<span>
+						<a href="https://validator.w3.org/check/referer">
+							<img style="border:0;width:88px;height:31px"
+								src="https://www.w3.org/Icons/valid-html401"
+								alt="Valid HTML!" />
+						</a>
+					</span>
+					<span>
+						<a href="https://jigsaw.w3.org/css-validator/check/referer">
+							<img style="border:0;width:88px;height:31px"
+								src="https://jigsaw.w3.org/css-validator/images/vcss"
+								alt="Valid CSS!" />
+						</a>
+					</span>
+				</p>
 			</div>
 		</main>
 	</body>