platform-guideline checked

Microsoft Support: Control data entry formats with input masks

Documents input masks as strings of placeholder and literal characters that constrain accepted values, with examples for phone numbers, stored-versus-displayed literals, and warnings against masks when users need exceptions or date picker behavior.

Open source

Pattern Decisions This Source Supports

Pattern Supported decision Required contract Claim note
Date input Choose date input for exact dates users already know or can find quickly. Typing, paste, selection, deletion, undo, and correction happen inside each part without automatic focus movement. Microsoft input-mask guidance helps distinguish rigid placeholder masks from flexible date-part entry.
Input mask Choose input mask when the value has a stable, narrow structure with predictable character classes and grouping. Typing valid characters fills the next available mask slot and inserts literal separators automatically. Microsoft documents masks as placeholder and literal-character constraints, including canonical storage choices and warnings against exceptions or date picker conflicts.

Evidence Role

This source is treated as platform-guideline evidence. Use it to validate the decision rules above, not as a visual style reference.

Publisher: Microsoft. Last checked: .