Skills and competencies tree for e-Learning

I think there is a problem in e-learning. There is no standard of skills and competencies recognition and comparing.
I did small  research on this problem.


Skills vs Competencies.
I wanted to be sure that i understand "skill" and "competence" terms correctly. This publication helped me to understand the difference.


What is the problem.
Now we have thousands of online courses. Some of them teach the same or similar things. BUt it is difficult to compare 2 courses from different vendors. 
For example, one course is named "PHP development" and other is named "PHP development". But PHP development competency has many different levels. Someone can be good in core PHP developement. Someone other can be good in Zend framework developement. And there are different levels of mastery in technology. 
How to understand if the online course is good to me? What background skills do i need to start the course?
Of course, every online course has description. But what if i search in database of 1000 courses? I need some standardized criteria. 


Possible solution.
It would be good if every online course has some standard tags associated with it. Like: "Core PHP developement level3", background required "Core PHP developement level2". Or "Zend Framework level2", background required  "Zend Framework level1" and "Core PHP developement level2".
In this case if i have the database of courses and skills tags associated with it i can easy find what courses are good for me with my existent background.


I think the solution of this problem is developing of some Skills Tree standard document . 
I tried to learn if there is such existent document.

Existent standards.
I googled some phrases like "skills tree", "competencies tree", "skills list standard" etc.
I didn't find one widely used standard of skills naming and descriptioning.
The best i found is DISCO http://www.skills-translator.net/?locale=en_GB.
But this is not standard. This can be good base of some international standard.
Scientific research.
I see many scientific articles on this subject about such problem exists and needs to be solved. But no one agreed standard. There are many projects and plans to solve this problem.
Many articles can be found in Google Academy
http://scholar.google.com/scholar?q=competencies+and+skills+&btnG=&hl=uk&as_sdt=0&as_vis=1

Government standards.
Also i see some standards developed by different govenrments. Especially many references to Australia competencies recognision documents. I think this is because of Australia immigration program that needs recognition of education level.

Video Game industry.
Video game industry has own concept of skills tree. Skills tries are used in strategies to "develop" heroes. Skills networks are good example of how skills and competensies tree should look like.

What i would like to have.
Ideally, i would like to have some document (probably, XML) released on some open licence like GNU and maintained by some independed organization. This document would contain full list of all existent skills and relations between them (parent-child dependencies). This document would need to be updated all the time, because new skills appear.


<?xml version="1.0"?>
<skills>
   <skill id="programming_php_core_l2">
      <author>Roman Doubush</author>
      <title>PHP Core Programming Level2</title>
     <required>programming_php_core_l1</required>
     <required>programming_algorithms</required>
     <required>programming_php_basics</required>
      <section>IT</section>
      <category>Programming</category>
      <publish_date>2000-10-01</publish_date>
      <description>PHP Core Programming Level2</description>
   </skill>
<skills>


Interesting links:
http://www.economist.com/node/12231124
http://www.cs.ny.gov/successionplanning/workgroups/competencies/competencylist.html