From the Encyclical Letter of the 1878 Lambeth Conference (Section 1.5)
There are certain principles of church order which, your Committee consider, ought to be distinctly recognised and set forth, as of great importance for the maintenance of union among the Churches of our Communion.
1. First, that the duly certified action of every national or particular Church, and of each ecclesiastical province (or diocese not included in a province), in the exercise of its own discipline, should be respected by all the other Churches, and by their individual members.
2. Secondly, that when a diocese, or territorial sphere of administration, has been constituted by the authority of any Church or province of this Communion within its own limits, no bishop or other clergyman of any other Church should exercise his functions within that diocese without the consent of the bishop thereof.
3. Thirdly, that no bishop should authorise to officiate in his diocese a clergyman coming from another Church or province, unless such clergyman present letters testimonial, countersigned by the bishop of the diocese from which he comes; such letters to be, as nearly as possible, in the form adopted by such Church or province in the case of the transfer of a clergyman from one diocese to another.
It's worth having a boo at Fr. Haller's further commentary. I will simply note that attempts at creating a centralized and authoritarian Anglican Communion go back a fair ways. Several Lambeth Conferences saw attempts to create an Anglican magisterium of one sort or another. We used to have the good sense to say a loud and clear "no."