Below is from the definition:

Article 4.1 An article of the Convention stipulating general commitments assumed by all Parties, developing or developed.

Below is from the definitions:
Article 4.2
An article of the Convention stating the specific commitments of developed-country (Annex I) Parties only -- notably that they would take measures aimed at returning greenhouse-gas emissions to 1990 levels by the year 2000.

Below are Article 4.1 and 4.2 from Kyoto Protocol:

Below is from the definitions:

Article 6 Supervisory Committee
A committee providing international oversight of "track-two" joint implementation projects. Joint implementation projects are carried out by sponsoring and recipient developed countries under Article 6 of the Kyoto Protocol -- with the recipient likely to be a country with an "economy in transition". Track-two is used if one or both of the countries does not meet requirements for the standard ("track one") joint implementation programme. See track two.

From the Kyoto Protocol - Track two also known as Joint Implementation:

The mechanism known as “joint implementation,” defined in Article 6 of the Kyoto Protocol, allows a country with an emission reduction or limitation commitment under the Kyoto Protocol (Annex B Party) to earn emission reduction units (ERUs) from an emission-reduction or emission removal project in another Annex B Party, each equivalent to one tonne of CO2, which can be counted towards meeting its Kyoto target. Joint implementation offers Parties a flexible and cost-efficient means of fulfilling a part of their Kyoto commitments, while the host Party benefits from foreign investment and technology transfer....
Link: http://unfccc.int/kyoto_protocol/mechanisms/joint_implementation/items/1674.php