FPF Reference

    Expansion for

    Preface node heading:expansion-for-card-key:79903

    What this page is

    This is generated FPF reference text from the specification preface or supporting sections. It helps interpret FPF; it is not FPF Reference product documentation.

    Methodology

    Use it to understand how the specification wants to be read, then return to a route, pattern, or work packet for active work. Cite generated IDs only when the wording changes the task decision.

    Content

    ```

    ### Practical-Use Cards is a group inside the one Practical entries set, not another front door or selectable key. Omit the group when the product selects no cards. The card's canonical structural field is Mantra; its value begins directly with the repeatable wording and needs no Local/Long prefix. A local reminder for one direct pattern or bounded result may remain in that pattern, an ordinary entry, or other teaching material, but it does not by itself select the richer card form. [E.11](/generated/patterns/E.11) owns this content decision.

    Every selectable ordinary entry and card shares one product-wide semantic-key namespace. The product declaration assigns each key one form, so a key cannot occur as both H3 and H4. An H5 expansion repeats its enclosing card key only to attach optional explanation; it is not another selectable occurrence. A card has zero or one expansion. Its compact portion ends after Stop or return; the expansion ends at the next H4-or-higher heading or the end of the group. The expansion may explain branch choices, examples, or exact result support, but cannot contain another H4 card or H5 expansion.

    The product-language application declares one deterministic reading-burden measure and two maxima: one for the mantra and one for the complete compact card. The measure must suit the publication language; whitespace counting is suitable only where it meaningfully measures reading burden. The maxima protect scanability and recall. They are not targets, proof of reader value, a fixed card count, or authority to delete a choice-changing distinction. Content that a compact card cannot carry truthfully returns to the direct patterns or, only when first choice needs it, the same-key expansion.

    Applying this grammar does not select a card, prove that the examples cover the product, or show that every cited pattern is needed in a particular case. [E.11](/generated/patterns/E.11) defines the direct-entry/card comparison, cross-pattern mnemonic-gain test, and non-exhaustive discoverability purpose. The product-specific E.4 pattern declares its selected example keys, forms, reading-burden measure, and two limits. A validator consumes those values and checks structure; it does not decide content value.

    This profile keeps structural field keys in canonical English. A translation may translate surrounding prose and values and may add a human-readable gloss, but it does not silently replace or reorder the field keys. A translated structural-key profile needs a separately selected recovery and checking rule. Test translated and low-tool publications with actual readers and navigation tools rather than treating English parser success as accessibility evidence.

    Last Updated: 2026-09-03 — upstream FPF commit b999972c (github.com/ailev/FPF)