It has been since long time some CSS attributes are missing from code completion in PHPEd, even in v14 now.
If the site is configured for CSS3/HTML5, there is absolutely no sign of position, border-collapse and many others. 'position' itself seems to be completed now in 14, although not syntax colored. This seems as a chronic issue for long time.
Now I see things like border-collapse don't even auto complete after being added to CSS3 reserved words list in Settings.
Before, if I added it to the settings, it got colored but not completed in code completion at all. Now this holds true for the other attributes like border-collapse. What's with the CSS parser in phped 9-14?

Ok, I see the phped.rel workaround to add the additional properties to the CSS3 definition. It is Ok enough, although not supposed to dive so deep to add something that as much used even in CSS3 as things like background.