I agree with your solution. Wheevern I come across similar terms and phrases, I translate them into English and then I ask myself if the translated literal version ever appears in similar situations.

1.3.2. Subscribers and end users
Seal Certificates are destined for different Entities and Bodies within Social Security, covering at least the Subdirectorate-General level.
For the purposes of this Policy, the certificate subscriber and owner shall be considered the Social Security Entity or Body in whose name the certificate is issued.
Likewise, the certificate applicant shall be considered the physical person duly tasked with and accredited to completing the request for a certificate as representative of said Entity or Body.

http://www.seg-social.es/prdi00/groups/public/documents/bina...

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Note added at 1 hr (2018-02-13 14:22:48 GMT)
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Sorry, I meant to write 'whenever'...

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Note added at 1 hr (2018-02-13 14:28:37 GMT)
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Registration Authority (RA) - A company or individual delegated by a Certificate Authority to verify the identity of a Certificate applicant.

https://www.gov.uk/government/uploads/system/uploads/attachm...

Identity Authentication and 'E-Commerce'

Method of Communicating Application: The IA communicates a certificate prototype (unsigned) and a subscriber agreement to the certificate applicant. By completing this on-line dialog via a secure Web channel, the certificate applicant then affirms that (i) the certificate applicant information is accurate and (ii) he or she has read, understands, and agrees to the term of the subscriber agreement. Upon completion of specified validation procedures, the IA sends E-mail to the E-mail address that was provided by the certificate applicant in the certificate application. This E-mail message contains a PIN (and optionally, a draft of information content to be included in the certificate) that authorises the certificate applicant to obtain a certificate from the IA.

https://warwick.ac.uk/fac/soc/law/elj/jilt/1998_3/ford/table...

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Note added at 1 day 6 hrs (2018-02-14 19:16:13 GMT) Post-grading
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I definitely wouldn't omit it on a contract but the language used on application forms is usually short and sweet.