slackpkg slackware64 packages masked but in changelog.txt

'slackpkg upgrade-all' shows packages that are available for upgrade, such as glibc, but are not installed. glibc appears in the base install repository file tree.
When 'slackpkg search glibc' is run the following is returned:

[inst] multilib : aaa_glibc-solibs-2.33_multilib-x86_64-1alien
[inst] multilib : glibc-2.33_multilib-x86_64-1alien
[inst] multilib : glibc-i18n-2.33_multilib-x86_64-1alien
[inst] multilib : glibc-profile-2.33_multilib-x86_64-1alien
[inst] slackware64 : glibc-zoneinfo-2021a-noarch-1
[mask] slackware64 : aaa_glibc-solibs-2.33-x86_64-2
[mask] slackware64 : glibc-2.33-x86_64-2
[mask] slackware64 : glibc-i18n-2.33-x86_64-2
[mask] slackware64 : glibc-profile-2.33-x86_64-2

I cannot remember why or how they were masked.
I seem to remember ferreting this out before, but can't find the reason.
Should the following packages be installed?:
Thu Apr 1 23:50:48 UTC 2021
a/aaa_glibc-solibs-2.33-x86_64-2.txz: Rebuilt.
ap/inxi-20210329_a539c8fd-noarch-1.txz: Upgraded.
l/glibc-2.33-x86_64-2.txz: Rebuilt.
l/glibc-i18n-2.33-x86_64-2.txz: Rebuilt.
l/glibc-profile-2.33-x86_64-2.txz: Rebuilt.
If they are, I am also trying to understand how they got masked.