For SINP, how Can I prove English is the principal language of communication?

[Jewel]

I am looking for your great help and valuable suggestions.

In SINP family category application guide there is a few options have been mentioned to prove applicant's English language ability. Among the five options, one option is :

Language Credentials
Employment references with English as the principal language of communication.

Regarding this option I wrote to SINP authority and in reply they agreed that I can supply an employer reference to prove English language ability.

Now I want to know from all of you guys, how can I prove that. Pls note I have been working in a shipping company for the last 7 years. Fyi, shipping company is the responsible for international sea transportation of goods/cargo, we have service to various destinations worldwide and obviously our principal language is English, used in daily correspondences/emails/telephone and in other communications etc. Be it also mention that we have overseas offices world wide.

Now I am confused, how can I show employment references that English is the main language of communication. Whether I should collect a letter from my employer describing that....or what kinds of documents I can attach with this letter.

Pls.. pls.. advise , I would be so grateful to you.

[pakistan]

Perhpas i already discussed this topic you do not need any specific documents to prove english... your education and work experience documents as usual shall work....

[Jasper]

If your employer writes "English is your main language of communication at work" and "you have been working for the company for ... years" etc, it means that you are fluent in English and the reference letter will suffice. I don't think you will need any other document.

[Jewel]

Dear pakistan and Jasper,

Thanks both of you, for your kind advise.

BC guy, Leon, PMM,

Would like to have some comments from you. Pls reply...

Best Rgds,