5.9.3: "md0:" is showing in dmesg/printk but with no other information is provided

Kernel: 5.9.3
Arch: x86_64

These are showing up in dmesg every so often and they are not
associated with any type of message/alert or user associated action.
What is causing this & why are there no details associated with this
message?

[Wed Nov  4 17:05:56 2020]  md0:
[Thu Nov  5 08:23:32 2020]  md0:
[Thu Nov  5 13:12:00 2020]  md0:
[Sat Nov  7 06:53:59 2020]  md0:
[Sat Nov  7 06:54:07 2020]  md0:
[Tue Nov 10 08:09:27 2020]  md0:
[Wed Nov 11 12:43:06 2020]  md0:

Regards,

Justin.