out of place mx records.

[Gregory Machin]

Hi.
I have taken over some dns servers, and the process of doing upgrade,
half way through the process..

I have a question about the zone files , as there is some
configuration here that I have not seen before and seems out of place.

here is an excerpt of the zone file

$TTL 14400

@		IN	SOA	example.com. postmaster.example.com. (
				2010042142	; Serial
				3600		; Refresh (1 hours)
				1200		; Retry   (20 minutes)
				1728000		; Expire  (20 days)
				14400     	; Minimum (4 hours)
                                )
		IN	NS	ns1.example.com.
		IN	NS	ns2.example.com.
;		IN	NS	ns1.catalyst.net.nz.

		IN	MX	10 mail01.example.com.
		IN	MX	10 mail02.example.com.
;		IN	MX	20 mail03.example.com.

		IN	A	202.xx.xx.2

ns1		IN	A	192.168.xx.xx	
ns2		IN	A	192.168.xx.xx	

listserv        IN	A	202.xx.xx.2
		IN	MX	10	mcvpemr01	
		IN	MX	10	mcvpemr02	
cache           IN	A	202.xx.xx.1
		IN	MX	10	mcvpemr01	
		IN	MX	10	mcvpemr02
captaincomet	IN	A	202.xx.xx.1
		IN	MX	10	mcvpemr01
		IN	MX	10	mcvpemr02
louie		IN	A	202.xx.xx.1
		IN	MX	10	mcvpemr01
		IN	MX	10	mcvpemr02
mail01          IN      A       192.168.xx.xx
		IN	MX	10	mcvpemr01	
		IN	MX	10	mcvpemr02
mail02          IN      A       192.168.xx.xx
		IN	MX	10	mcvpemr01	
		IN	MX	10	mcvpemr02
nelson          IN	A	202.xx.xx.1
		IN	MX	10	mcvpemr01
		IN	MX	10	mcvpemr02
	

My question is why would "IN    MX    10    mcvpemr01" and "IN    MX
 10    mcvpemr02" be repeated trough the zone file surely this is
redundant ?


Thanks
Greg