input type="string" is it correct input type?

Currently i am having problem in firefox browser if i use: its automatically displaying the value the password and email when saving the password in firefox

<input type="text" value= email/>
<input type="text" value= mobilenumber/>

I solved the problem by using it as:

<input type="string" value= email/>
<input type="string" value= mobilenumber/>

Now i need a source which can tell like there is an input type= "string".

So please can anyone help me finding the link to source.