This prints every bit of the kernel tainted info:

1for i in $(seq 18); do echo $(($i-1)) $(($(cat /proc/sys/kernel/tainted)>>($i-1)&1));done

As an example:

1[ecomaikgolf@laptop ~/]$ for i in $(seq 18); do echo $(($i-1)) $(($(cat /proc/sys/kernel/tainted)>>($i-1)&1));done
20 0
31 0
42 0
53 0
64 0
75 0
86 0
97 0
108 0
119 0
1210 0
1311 0
1412 0
1513 0
1614 0
1715 0
1816 0
1917 0

Every bit shows a reason why the kernel got tainted

Bit tables: https://docs.kernel.org/admin-guide/tainted-kernels.html

Source: https://docs.kernel.org/admin-guide/tainted-kernels.html