Validity period of the certificate is three years.

证书有效期三年。

The Type Certificate has a validity period of two years.

类型认证有效期为两年。

The renewal period must be less then the validity period.

续订期必须短于有效期。

Maximum number and validity period of downloads can be configured.

可设置大量有效的下载。

A period of storage requirements, but also indicate the validity period.

有贮存期限要求的，还须注明有效期。