Baseline Requirements pkimetal インストール・利用方法
How to install and use pkimetal.
S/MIME Certificate
Baseline Requirements 
Baseline Requirements pkilintのインストールと利用方法（Rocky Linux 8.9）
How to install and use pkilint. (Rocky Linux 8.9)
S/MIME Certificate S/MIME Baseline Requirementsが2023/09/01に発効
S/MIME Baseline Requirements to take effect September 1, 2023.
S/MIME Certificate S/MIME証明書の有効期間が1185日以下に（2022/04/01以降）
S/MIME certificates have not a validity period greater than 1185 days.
S/MIME Certificate S/MIME証明書の取得・設定方法【無料】
How to obtain and set up an S/MIME certificate [free of charge].