This will read: EXTENSION OF STAY PERMITTED UP TO .....

HOLDER MUST LEAVE THE KINGDOM WITHIN THE DATE SPECIFIED HEREIN. OFFENDERS WILL BE PROSECUTED.

(The date will be 365 days from your first entry.)

IF you leave the country for even 1 day, you must apply before, for a RE-ENTRY PERMIT, which will allow you to return to LoS under the previous conditions.

This permit will have the same expiry as your permission to stay and your new mermit will have the same date, as well.

The 90-days reporting has nothing to do with your permission to stay, as such.

If you stay in the country, you must report your address every 90 days. (Text I showed in my earlier post in the thread.) If you leave the country and come back on your re-entry permit, you do not need to report your address until 90 days AFTER this re-entry because you gave your address in the arrival card (TM 6-form). (Unless you change address)

Sounds easy?

It's quite clear to me, however what confuses me is that I just re-entered the country on April 26th and immigration didn't remove the old receipt of notification (dating February 26th). So I read I should notify again on May 26th, but it should be instead July 26th. Or am I missing something?

You pulled up a six year old thread to ask this?

Immigration never pulls a 90 day report from your passport - you present that report at your next due date (90 days from entry) and if they do not notice the reason you point out that you were not in Thailand on that date and returned 90 days ago.