diff --git a/2. IPv6 Basic Technology/Extension headers and options.md b/2. IPv6 Basic Technology/Extension headers and options.md
index a3f2b33..7b587ad 100644
--- a/2. IPv6 Basic Technology/Extension headers and options.md	
+++ b/2. IPv6 Basic Technology/Extension headers and options.md	
@@ -4,7 +4,7 @@ As explained in [2. Packet Format](../2.%20IPv6%20Basic%20Technology/Packet%20Fo
 
 - Hop-by-Hop (HBH) options, for packet-level options that should be examined by every node on the path. The defined options are listed, with references, at [IANA](https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2). Option 0x05 "Router Alert" is perhaps the most interesting; it is intended to warn every router on the path that the packet may need special handling. Unfortunately, experience shows that this extension header can be problematic, and that many routers do not in fact process it. Indeed, [RFC8200](https://www.rfc-editor.org/info/rfc8200) states that "it is now expected that nodes along a packet's delivery path only examine and process the Hop-by-Hop Options header if explicitly configured to do so."
 
--- Router Alert types have their own registry at [IANA](https://www.iana.org/assignments/ipv6-routeralert-values/ipv6-routeralert-values.xhtml).
+  Router Alert types have their own registry at [IANA](https://www.iana.org/assignments/ipv6-routeralert-values/ipv6-routeralert-values.xhtml).
 
 - Fragment header, when a packet has been fragmented (which happens only at the source, if the raw packet exceeds the known MTU of the transmission path, which is at least the IPv6 minimum MTU of 1280 bytes). IPv6 fragmentation is significantly different from IPv4 fragmentation, which may occur anywhere along the path. The technical details are described in [STD86](https://www.rfc-editor.org/info/std86). Of course, fragmentation interacts with PMTUD (Path Maximum Transmission Unit Determination) so the lazy solution is to never exceed the 1280 byte limit. For PMTUD, see [STD87](https://www.rfc-editor.org/info/std87), [RFC8899](https://www.rfc-editor.org/info/rfc8899), and (for horror stories) [RFC7690](https://www.rfc-editor.org/info/rfc7690). Also see "IP Fragmentation Considered Fragile" for operational recommendations \[[BCP230](https://www.rfc-editor.org/info/bcp230)].