How do you mark a website you developed in order to show it as a proof of your work

Question

Well, that is, I have developed some websites and what I usually do when someone is going to hire me is to show him/her some of my previous and similar jobs I've done in order to make them feeling comfortable.

Today I was talking with a guy and I did what I mentioned before, then he asked me: "How can I know you really did those website", and actually I couldn't give him a nice answer since all I have is from those websites are: pictures, documents and some Skype conversations. Most of the times it is enough.

What do you do to water proof your job?

EDIT

I researched about this topic and found a guy who write a tag like this:

<meta name="generator" content="Developer Name" />

Is it a good or a bad idea?

Answer 1

Don’t use the metadata name generator. HTML5 defines that the value is for the software package (e.g., the CMS) used to generate the document, not for a person.

Don’t use the metadata name author (as suggested by Moz). HTML5 defines that it’s for the page’s author. While it doesn’t define the term "author", it’s safe to assume that the web designer/developer is not the author of the document (as in content).

Alternatives?

• You could use the metadata name designer:

  Credits the designer(s) responsible for the visual presentation of a website.

  It’s registered on MetaExtensions, so you are allowed use it in HTML5.

  <meta name="designer" content="Designer name">
  

• You could use the metadata name web_author:

  Credits the developer(s) responsible for the technical design of a website.

  It’s registered on MetaExtensions, so you are allowed use it in HTML5.

  <meta name="web_author" content="Developer name">
  

• You could add/edit the file humans.txt of the website (as also suggested by w3d) and include your name and website URL.

• You could include your name/URL on a page of the website (e.g., on the Impressum or a similar page that contains information about the site/accessibility/privacy policy/terms of service/authors/etc.).

Of course, no matter which option you use, you should ask your client for permission.

Answer 2

Two unobtrusive ideas:

• Include an HTML comment in the page source.
• humans.txt

The problem with having a visible link to your site (in the footer) is that it's less professional.

Answer 3

Ask your existing clients if they are willing to provide references or testimonials to prospective new clients. Some will be willing and some will not be. But it's powerful when an existing client not only says that you did their web site, but how pleased they are with it and how easy you were to work with, etc. Of course, this works best if your clients were happy with you and there were no big problems (e.g. they took months to pay you).

Answer 4

How about this tag:

<meta name="author" content="Developer Name">

In my opinion is better than the generator one, but it can conflict with the author of the data, not the webpage.

Other method I use, is on the footer I add a little logo that links to my personal website. But of course you need permition from your client to do so, but if asked nicely, I am pretty sure they will understand your purpose of adding it.