Just mark the ARCNET values as reserved.

Don't go into detail for the Linux encapsulation; a full description
would be long and painful, and it's probably not hugely relevant these
days.  Just speak of "BSD encapsulation" and "Linux encapsulation", just
as the tcpdump.org list now does.

linktypes.csv

@@ -5,7 +5,7 @@
 |LINKTYPE_PRONET|4|Reserved for Proteon PRONet Token Ring|
 |LINKTYPE_CHAOS|5|Reserved for MIT Chaosnet|{{AIM-628}}
 |LINKTYPE_IEEE802_5|6|IEEE 802.5 Token Ring|
-|LINKTYPE_ARCNET_BSD|7|ARCNET Data Packets with BSD encapsulation|
+|LINKTYPE_ARCNET_BSD|7|Reserved for ARCNET Data Packets with BSD encapsulation|
 |LINKTYPE_SLIP|8|SLIP|{{LINKTYPE_SLIP}}
 |LINKTYPE_PPP|9|PPP|{{?RFC1661}}/{{?RFC1662}}
 |LINKTYPE_FDDI|10|FDDI: per ANSI INCITS 239-1994|
@@ -43,7 +43,7 @@
 |LINKTYPE_AURORA|126|Reserved for Xilinx Aurora link layer|
 |LINKTYPE_IEEE802_11_RADIOTAP|127|Radiotap header, followed by an 802.11 header|{{Radiotap}}
 |LINKTYPE_TZSP|128|Reserved for Tazmen Sniffer Protocol|
-|LINKTYPE_ARCNET_LINUX|129|ARCNET Data Packets, per RFC 1051 frames w/variations|
+|LINKTYPE_ARCNET_LINUX|129|Reserved for ARCNET Data Packets with Linux encapsulation|
 |LINKTYPE_JUNIPER_MLPPP|130|Reserved for Juniper Networks|
 |LINKTYPE_JUNIPER_MLFR|131|Reserved for Juniper Networks|
 |LINKTYPE_JUNIPER_ES|132|Reserved for Juniper Networks|

linktypes.xml

@@ -98,7 +98,7 @@ Number
 : 7
 
 Description
-: ARCNET Data Packets with BSD encapsulation
+: Reserved for ARCNET Data Packets with BSD encapsulation
 {: spacing="compact"}
 
 
@@ -590,7 +590,7 @@ Number
 : 129
 
 Description
-: ARCNET Data Packets, per RFC 1051 frames w/variations
+: Reserved for ARCNET Data Packets with Linux encapsulation
 {: spacing="compact"}