{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.merlon","code":"thing-q23419","url":"https://ver.cy/models/thing/q23419/","name":"merlon","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.3","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.BLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"The solid upright section of a battlemented parapet on a castle, fortification or city wall, standing between the open gaps called crenels or embrasures, together forming the crenellation that sheltered defenders while they observed and fought through the gaps; merlons vary in shape from plain rectangles to the swallowtail Ghibelline form of Italian fortifications and often carried arrow slits, and the registry parent trumeau is a misclassification.","purpose":"Let an agent explain merlons and crenellation, describe forms and regional styles, relay their defensive function and later decorative use, and distinguish merlons from crenels, trumeaux and other wall elements.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Part of crenellation","Shelter for defenders","Regional forms","Later decorative use"],"structure":{"bundles":[{"id":"understand","name":"Understand","description":"What a merlon is.","layers":[{"id":"definition","name":"Definition","description":"Definition.","findings":[{"id":"definition-finding","name":"Definition","description":"Definition.","questions":[{"text":"What is a merlon, and how does it relate to crenels and crenellation?","kind":"definition"},{"text":"Is the element a merlon, a crenel or another wall feature?","kind":"boundary"}]}]},{"id":"forms","name":"Forms","description":"Forms.","findings":[{"id":"forms-finding","name":"Forms","description":"Forms.","questions":[{"text":"What forms do merlons take, including Guelph and Ghibelline shapes?","kind":"definition"},{"text":"Which entry fits the specific fortification?","kind":"action"}]}]}]},{"id":"function","name":"Function","description":"Defensive function.","layers":[{"id":"defence","name":"Defence","description":"Defence.","findings":[{"id":"defence-finding","name":"Defence","description":"Defence.","questions":[{"text":"How did merlons shelter defenders, and how did arrow slits and hoardings extend them?","kind":"provenance"},{"text":"Which entry fits medieval fortification?","kind":"action"}]}]},{"id":"evolution","name":"Evolution","description":"Evolution.","findings":[{"id":"evolution-finding","name":"Evolution","description":"Evolution.","questions":[{"text":"How did crenellation develop and decline with changes in siege warfare, as historians describe?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]}]},{"id":"style","name":"Style","description":"Regional and decorative.","layers":[{"id":"regional","name":"Regional","description":"Regional styles.","findings":[{"id":"regional-finding","name":"Regional","description":"Regional.","questions":[{"text":"How do merlon forms differ across Europe, the Islamic world and Asia?","kind":"provenance"},{"text":"Which sources are cited?","kind":"provenance"}]}]},{"id":"decorative","name":"Decorative","description":"Decorative use.","findings":[{"id":"decorative-finding","name":"Decorative","description":"Decorative.","questions":[{"text":"How were merlons used decoratively in Gothic Revival and later architecture?","kind":"provenance"},{"text":"Which entry fits Gothic Revival architecture?","kind":"action"}]}]}]},{"id":"context","name":"Context","description":"Law and conservation.","layers":[{"id":"licence","name":"Licence","description":"Licence to crenellate.","findings":[{"id":"licence-finding","name":"Licence","description":"Licence.","questions":[{"text":"What was the medieval English licence to crenellate?","kind":"provenance"},{"text":"Which entry fits licence to crenellate?","kind":"action"}]}]},{"id":"conservation","name":"Conservation","description":"Conservation.","findings":[{"id":"conservation-finding","name":"Conservation","description":"Conservation.","questions":[{"text":"How are battlements conserved and restored?","kind":"provenance"},{"text":"Which entry fits heritage conservation?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Document and measure merlons and the parapet they stand in for a heritage survey.","Explain battlement terms and regional forms from architectural sources."],"mustNot":["Climb on or lean against a merlon or parapet that has not been assessed as stable.","Allow visitors near an open crenel without a safe barrier.","Rebuild, point or cap historic masonry without heritage consent.","Present a modern decorative battlement as medieval fabric."],"requiresHuman":["Any repair, consolidation or change to historic masonry.","Opening a wall walk to visitors."]},"ethics":{"considerations":["Loose parapet stone falls on people below, and the openings are a fall hazard.","Over-restoration erases the evidence that gives a fortification its history."],"affectedParties":["Visitors on the wall walk","People below the wall","Conservators"]},"owners":{"steward":"The owner or heritage body that keeps the structure, under the monument authority.","roles":[],"masterSystems":["National heritage and monument registers"]},"relations":[{"target":"Q2167035","type":"parent","note":"registry parent class"},{"target":"trumeau","type":"related","note":"in registry terms, a misclassification"},{"target":"battlement","type":"related","note":"with crenels"},{"target":"crenel","type":"related","note":"the gap"},{"target":"castle","type":"related","note":"and city walls"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.merlon","Wikidata: Q23419 (https://www.wikidata.org/wiki/Q23419)"]},"properties":{"applicability":"required","items":["Merlon height:  m - Measure vertically from the adjacent crenel sill level to the highest surviving point.","Merlon width:  m - Measure horizontally between the adjoining crenels and specify the measurement elevation for shaped examples.","Merlon thickness:  m - Measure between the inner and outer faces perpendicular to the parapet alignment."]},"recognition":{"applicability":"required","items":["Solid part of a battlement between gaps","Rectangular, swallowtail and pointed forms","The crenel is the gap; a trumeau is a central pier of a doorway, and the registry parent is wrong","A raised block of masonry along the top of a wall, alternating with gaps."]},"capabilities":{"applicability":"required","items":["explain the element and crenellation","describe forms and styles","relay function and history","distinguish from related elements"]},"hazards":{"applicability":"required","items":["Confusing merlon with crenel","The registry parent trumeau is wrong","Decorative crenellation mistaken for defensive"]},"interfaces":{"applicability":"required","items":["Heritage protection of fortifications","Historical licences to crenellate in England"]},"context":{"applicability":"required","items":["Not applicable; a defensive architectural element.","plain rectangular merlons","Guelph square and Ghibelline swallowtail merlons","merlons with arrow slits","stepped and pointed merlons in Islamic and other traditions","decorative merlons on Gothic Revival buildings"]}},"sources":[{"title":"Wikidata item Q23419: merlon","url":"https://www.wikidata.org/wiki/Q23419","note":"identity and sense of the item"},{"title":"Wikipedia: Merlon","url":"https://en.wikipedia.org/wiki/Merlon","note":"general description of the item"}],"openQuestions":["Should the registry parent be corrected to battlement?","How should architectural references be linked?","How should regional forms be recorded?"],"resources":{"spec":"/models/things/publications/thing-q23419/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q23419/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-13T00:32:31Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:28+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}