The catalogue is based on a structured methodological approach that combines systematic data collection, comparative analysis and continuous verification. Its development reflects an ongoing process rather than a fixed, final publication.

Information has been compiled from a broad range of sources, including published catalogues and philatelic literature, auction results, dealer listings and the examination of original material in private and public collections. In addition, feedback and contributions from collectors have been taken into account where relevant.

The classification of philatelic items follows a consistent framework based primarily on chronological order of issue, supplemented by official classifications where available. Material is further organized into typological groups such as postage stamps, postal stationery, first day covers and booklets. Where necessary, additional levels of subdivision are introduced to reflect specific varieties and distinctions.

The identification of varieties is based on observable physical characteristics, including differences in printing, perforation, paper, colour and overprints. These observations are supported, where possible, by references in philatelic literature and by comparison with multiple examples. In certain cases, the catalogue includes newly identified or previously undocumented varieties as part of the ongoing research process.

All data is subject to continuous verification and revision. Information is cross-checked across multiple sources and updated when new evidence or more accurate data becomes available. This ensures that the catalogue remains a reliable and evolving reference.

Price indications, where provided, are derived from observed market data such as auction results and dealer offerings, combined with an assessment of relative rarity and availability. These prices are intended as general guidance rather than fixed or definitive market values.

As a digital system, the catalogue allows for regular updates, corrections and the integration of new research findings. This dynamic structure is essential for maintaining accuracy and relevance in a continuously developing field.