How to remove the OBJ box from a WordPress title or post

The "OBJ" in a dotted box is a real character with a name: the object replacement character, U+FFFC in Unicode. The Unicode Standard describes it as a placeholder in text for an object, something that is not text, such as a picture set among the words. The text keeps the placeholder and the app keeps the object somewhere else.

It usually reaches WordPress in text pasted from another app, such as a word processor, a notes app or an email, or in text entered by dictation. The object stays behind and the placeholder comes along.

Unicode's own chart draws the character as the letters OBJ in a dashed box, and some fonts do the same. Others draw nothing. That is why the box can show in a browser tab, a search result or a shared link and be invisible in the editor.

Nothing on the site is broken. One stray character is stored in the text, and removing it is the whole fix.

Remove it from one post

The page's address does not need changing. WordPress leaves this character out when it makes a slug from a title.

Remove it from many posts at once

If the box is in dozens of titles, WP-CLI can remove every copy in one pass. It needs SSH access, and a backup of the database first, because the command cannot be undone. wp db export ~/before-obj.sql writes one to your home folder. If you have a staging copy of the site, run the command there first.

Copy this command from the page instead of typing it. The first pair of quotes holds the character itself, which may look like a box or like nothing at all in your terminal. The second pair is empty, so each copy is replaced with nothing.

wp search-replace '' '' --report-changed-only --dry-run

--dry-run reports the tables and columns that hold the character and how many replacements it would make, and saves nothing. If it finds none although the box is on the site, the character may not have survived the copy. Copy the command again.

When the report looks right, run the same command without --dry-run:

wp search-replace '' '' --report-changed-only

The command searches the tables WordPress itself registers, which hold titles, content, excerpts and the fields stored with each post. Add --all-tables-with-prefix to include tables that plugins have added. Then empty the site's cache.

Stop it coming back

• Paste as plain text. Use your browser's command for pasting without formatting, in its Edit menu or the menu that opens on a right-click. It leaves out formatting and embedded items, which is usually what the character stood for. Look over the pasted text all the same.
• Copy only the words. When you select text in the other app, leave out any picture, icon or attachment beside it.
• Read dictated text before you publish.