cff-version: 1.2.0
abstract: "<p>Reflectance and Transmission Imaging Spectroscopy (RIS and TIS) in the Visible and Near Infrared range (400-1000 nm, VNIR) of two pages containing hidden text in two Frisian legal codes from the Richthofen Collection (Leeuwarden, NL). Investigated were the <em>Fivelgo manuscript</em> (manuscript R 4) and the <em>Codex Phaesma </em>(manuscript R 8).</p><p><br></p><p>The data was acquired using a Specim IQ camera. </p><p><br></p>"
authors:
  - family-names: Alfeld
    given-names: Matthias
    orcid: "https://orcid.org/0000-0001-7974-9564"
  - family-names: de Almeida Nieto
    given-names: Luís Manuel
    orcid: "https://orcid.org/0000-0003-2748-3906"
title: "Reflectance and transmittance imaging spectroscopy of two medieval Frisian legal codes featuring hidden text"
keywords:
version: 1
identifiers:
  - type: doi
    value: 10.4121/3ee53917-a217-4b58-96c2-361ead8faf3b.v1
license: CC BY-NC 4.0
date-released: 2025-09-10