Duplicate entries in +REQUIRED_BY files

[Hans Lambermont]

Is it normal for +REQUIRED_BY files to have double entries in it ?

f.i. in /var/db/pkg> cat png-1.2.8_3/+REQUIRED_BY
ImageMagick-6.2.5.5_2
arts-1.5.1_1,1
boinc-client-4.68.20050601_3
boinc-setiathome-4.07.20050601_3
cairo-1.0.2_2
cairo-1.0.2_2
cups-base-1.1.23.0_8
cups-base-1.1.23.0_8
...

I noticed these while using portmaster version 1.1

regards,
  Hans Lambermont