The block editor stores your content as markup with comments in it, and most of the odd behaviour people report is that markup disagreeing with itself. These articles are about what the blocks really write.
SEO & Structured Data
WordPress Alt Text: Where It Lives and Why Your Edits Do Not Show
Alt text in WordPress is one postmeta row, copied into the post markup the moment you insert an image. That single fact explains why editing the library changes nothing on pages you already published, why an audit has two halves, and what to fix first.
Gutenberg Block Invalid Content: Validate and Repair Block Markup
The editor says a block contains unexpected or invalid content and stops there: no line, no attribute, no cause. Here is what it compared, why block markup drifts after a migration, and how to find the exact character that broke it.
Custom Post Type WordPress: Register It in Code, Not a Plugin
A complete register_post_type() snippet you can paste into a one-file plugin, plus an honest walk through the arguments that change real behaviour: why the block editor refuses to load without show_in_rest, and why every new single URL returns a 404 until the rewrite rules are flushed.
JSON Validator and Repair: What the Parser Actually Saw
Parsers name the character after the mistake, and PHP names nothing at all. The whole JSON grammar, the invisible bytes that break a file that looks perfect, the places WordPress hides JSON, and a validator that reports every fault in one pass.
Pasted text carries more than words: Word markup, PDF line breaks, tracking parameters, and a set of characters that render as nothing at all. What each one actually is, why WordPress makes some of it worse, and what to strip.
