Ideal method to pass validation

Hi all, I am new to trying to pass validation, at least in that I want  
a 100% solid report.

I am close, but I want to know the methods, and a link to notes or  
tech data is more than sufficient...

When new features are entered into html, such as some of the custom  
things webkit is doing, namely:

<input type="search" placeholder="Search..." autosave="bsn_srch"  
results="5" name="s" id="search" class="standard" size="15" />

As you can see, there are type attributes that are not known.  This is  
a Safari specific feature, I happen to like it.  I can see no harm it  
would cause to other browsers as it gracefully degrades.

Do I just ignore it, not pass validation, and know it is still ok as  
per my personal desires?  Are there hacks I can inject to force it to  
pass and maintain the features, or is that against the ideals of  
validation entirely?

Thanks
--
Scott
talklists@newgeo.com