Truncation hides overflow; it does not solve it

What it is

Truncation as hidden overflow occurs when clipping or an ellipsis removes visible collision but leaves the information incomplete. Truncation is a deliberate compression strategy only when the omitted part is safely inferable, recoverable elsewhere, and irrelevant to the choice at hand. Used as a universal localization patch, it converts a layout defect into content loss.

Why it happens

An ellipsis signals that content exists but carries none of the missing characters. Items sharing a prefix can become indistinguishable when their differentiating name, version, date, or action object lies at the end. Narrow screens, text enlargement, and longer translations move the cut point earlier, so a component that once lost a modifier can begin losing its core meaning. A full accessible name does not remove the scanning problem for sighted users, just as visible full text without an accessible name fails assistive-technology users.

Where it stops holding

Dense file lists and histories can reasonably truncate when the full value is reliably available through focus, expansion, or details and neighboring items remain distinguishable. Irreversible actions, amounts, dosages, safety warnings, legal consent, and recovery steps should not depend on hover for completion: touch, keyboard, and magnified use may not expose the same route. Multi-line clamping still removes information; it merely postpones the threshold.

Applying it

• Decide whether the missing text affects identification, choice, or risk; wrap, grow, or reflow critical copy instead of adding an ellipsis.
• When truncation is justified, choose tail, middle, or head-preserving behavior from the identifier structure; ordinary end ellipsis does not preserve the most discriminating segment automatically. Expose the full value to keyboard, touch, and screen readers.
• Do not use a tooltip as the sole remedy; provide matching full text in details, an expandable region, or the accessible name.
• Test with similar real names, long translations, enlarged text, and narrow screens; users must distinguish items and act without guessing.

Related

• Same group: S1.01.1 Translations of the same content vary substantially in length across languages · S1.01.2 Short labels expand proportionally more than long passages · S1.01.3 Containers fixed to source-language length inevitably overflow · S1.01.4 Layouts must be tested against the longest language, not the average
• Adjacent: J2.03 Text enlargement and reflow · T1.03 Trading concision against completeness
• Search terms: text truncation · text clamping · tooltip accessibility