OpenSSL/PEM

PEM stands for, it's a standard for a public-key cryptography.

Syntax
A PEM key must be stored in a file, preferably .pem, beginning and ending by these lines : -BEGIN CERTIFICATE REQUEST- ... -END CERTIFICATE REQUEST-

In Linux, we can identify the PEM certificates with the  command: file MyCertificate.crt MyCertificate.crt: PEM certificate request

Conversion
To convert a DER certificate to a PEM one: