ISAD(G) Archival Model

The isadg database in ABCD implements the General International Standard Archival Description (2nd Edition). Unlike library catalogs which deal with discrete items (books), this model is designed for hierarchical descriptions of archival funds.

Database Definition

• Internal Name: isadg
• Standard: ICA ISAD(G) 2nd Edition.
• Structure: Hierarchical (Multi-level description).
• Encoding: UTF-8.

1. The Hierarchical Model (Tree View)

The core feature of this database is the ability to link records in a "Parent-Child" relationship, creating a dendrogram (tree) structure in the interface.

Levels of Description

Defined in def/pt/nivel.tab. The system validates that a lower level is always linked to a higher level.

1. Fonds (F): The whole of the records (highest level).
2. Sub-fonds (SF): Major subdivision.
3. Series (S): Documents arranged in accordance with a filing system.
4. Sub-series (SS): Subdivision of a series.
5. File (D): An organized unit (Folder/Process).
6. Item (I): The smallest unit (Letter, Photo, Report).

Linking Mechanism

• Reference Code (Tag 11): The unique identifier of the unit (e.g., BR-RJ-001).
• Tree Construction: ABCD uses the reference code structure or a specific parent pointer field to build the visual hierarchy in the OPAC and Data Entry.

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2. Field Structure (FDT)

This implementation maps the 7 ISAD(G) areas directly to the Field Tags using a mnemonic logic: Tag XY corresponds to Area X, Element Y.

Area 1: Identity Statement (Tags 1x)

Defines "What is this unit?".

Tag	ISAD(G) Rule	Element Name	Description
11	3.1.1	Reference Code	Unique ID (Country-Repo-Collection-Item).
12	3.1.2	Title	Name of the unit.
13	3.1.3	Dates	Date of creation (Start/End).
14	3.1.4	Level of Description	Picklist (Fond, Series, Item...).
15	3.1.5	Extent & Medium	Quantity (e.g., "5 boxes", "300 photos").

Area 2: Context (Tags 2x)

Defines "Who created it and why?".

Tag	ISAD(G) Rule	Element Name	Description
21	3.2.1	Name of Creator	Authority controlled field (Person/Corporate).
22	3.2.2	Admin/Bio History	History of the creator.
23	3.2.3	Archival History	Custodial history (chain of ownership).
24	3.2.4	Acquisition Source	Donor or transfer origin.

Area 3: Content and Structure (Tags 3x)

Defines "What is inside?".

Tag	ISAD(G) Rule	Element Name	Description
31	3.3.1	Scope and Content	Summary of the subject matter.
32	3.3.2	Appraisal	Destruction or retention schedules.
33	3.3.3	Accruals	Expected future additions.
34	3.3.4	Arrangement	Internal organization system.

Area 4: Conditions of Access (Tags 4x)

Defines "Can I see it?".

Tag	ISAD(G) Rule	Element Name	Description
41	3.4.1	Legal Status	Laws affecting access (e.g., Secrecy Act).
42	3.4.2	Access Conditions	Restrictions (Public, Restricted, Closed).
43	3.4.3	Copyright	Reproduction restrictions.
44	3.4.4	Language/Scripts	Languages used in the documents.
45	3.4.5	Physical Characteristics	Conservation status (e.g., "Fragile").

Area 5: Allied Materials (Tags 5x)

Defines "Where are other copies?".

Tag	ISAD(G) Rule	Element Name
51	3.5.1	Location of originals
52	3.5.2	Existence of copies
53	3.5.3	Related units of description
54	3.5.4	Publication note

Area 6: Notes (Tags 6x)

• Tag 61: General Notes.

Area 7: Description Control (Tags 7x)

Defines "Who wrote this description?".

Tag	ISAD(G) Rule	Element Name
71	3.7.1	Archivist's Note
72	3.7.2	Rules or Conventions
73	3.7.3	Date of description

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3. Worksheets & Tabs

To make data entry manageable, the worksheet (isadg.fmt) is divided into logical tabs corresponding to the areas above, defined by the .tab files in def/lang/:

• Identificação (isadg.fdt tags 11-15)
• Contexto (acceso.tab tags 21-24)
• Conteúdo (alcance.tab tags 31-34)
• Acesso (instrumento.tab tags 41-45)
• Fontes Relacionadas (normas.tab tags 51-54)
• Notas/Controle

4. Indexing Strategy (FST)

The isadg.fst file defines how users can find these records.

Prefix	Field Name	Technique	Logic
(Text)	Global Search	Word (4)	Indexes Title, Scope, and History.
TI_	Title	Word (4)	Individual words from Tag 12.
CR_	Creator	Phrase (0)	Exact name from Tag 21.
DE_	Descriptors	Phrase (0)	Subject access points.
FE_	Dates	Numeric	Search by year/range (Tag 13).
LC_	Reference Code	Full	Exact search for ID (Tag 11).

5. Visualizing Data (PFT)

• isadg.pft: The main display format used in the Central module. It dynamically assembles the record, hiding empty fields and adding labels based on the active language (Tag 11 becomes "Reference Code:" or "Código de Referência:").
• publico.pft: A simplified format optimized for the OPAC, often suppressing administrative notes (Area 7).

Digital Objects

You can attach digital files (PDFs, Images) to any level of the hierarchy (e.g., a photo of the Item or a PDF finding aid for the Series) using the standard Tag 900+ digital library fields.