Complete required steps:

$-$ Create a new HTML form. The form should have two required fields: Group Name and Group Description.

$-$ The Group Name field should accept only letters, numbers, and spaces.

$-$ The Group Description field should accept only letters, numbers, spaces, and common punctuation marks. The Group Description field should have a minimum length of $10$ characters and a maximum length of $200$ characters.

$-$ When the form is submitted, the PHP script should perform the following steps:

a$.$ Validate the form data and throw an exception if any of the required fields are missing or contain invalid characters.

b$.$ Store the form data in an array variable.

Note that in this implementation, we are storing the form submissions in an array variable instead of a database.