Important: #101535 - Unused DB fields from tt_content removed

Description

The database table tt_content contains all necessary fields for rendering content elements.

Back with TYPO3 v4.7, a major feature to render certain Content Types in a more accessible way, funded by the German Government (BLE_) with the "Konjunkturpaket II" was merged into CSS Styled Content.

In this procedure, certain Content Types received new fields and rendering definitions, which were stored in the database fields accessibility_title, accessibility_bypass and accessibility_bypass_text.

When CSS Styled Content was removed in favor of Fluid Styled Content in TYPO3 v8, the DB fields continued to exist in TYPO3 Core, so a migration from CSS Styled Content was possible.

However, the DB fields are not evaluated anymore since then, and are removed, along with their TCA definition in tt_content.

If these fields are still relevant for a custom legacy installation, these DB fields need to be re-created via TCA for further use in a third-party extension.