Skip to content
Language:DeutschEnglish Last updated: 2026-10-23

Spreadsheets and presentations: formats and significant properties

This page sets out, for spreadsheets and presentations, which formats Anton prefers and accepts, which properties must be preserved, and what Anton measures or checks of them today. It belongs to the series per format category (anton#687), after images, PDF, text, and audio and video. Databases are not covered here.

Anton needs this for three things: to document what makes up a spreadsheet or presentation (NDSA Cn-1.1), to verify that it still does (Cn-2.1), and to prove after a migration that nothing significant was lost (media:migrate).

Formats

Spreadsheets

Level Format Condition
preferred ODS (OpenDocument Spreadsheet) without a password
preferred XLSX without a password
preferred CSV in UTF-8 for plain data, with a description
accepted XLS as long as LibreOffice reads it
accepted PDF/A only as an additional view beside the original

Presentations

Level Format Condition
preferred ODP (OpenDocument Presentation) without a password
preferred PDF/A-2u where the slides are fixed; see PDF
accepted PPTX, PPT as long as LibreOffice reads them

Spreadsheets: Preferred are ODS and XLSX in their original format. Only there do formulas, hidden rows and sheets survive; KOST recommends both and advises against converting between them. ODS comes first, as ODT does for text; NARA prefers it and rates it low risk, XLSX moderate. LibreOffice reads XLS; KOST advises converting it to XLSX, NARA only for versions before Excel 97. Under the principle it stays until it can no longer be read. For plain data without formulas or formatting, CSV in UTF-8 is the most durable format; NARA prefers it. Since CSV has no fixed standard and cannot be validated, the depositor supplies a description: delimiter, escaping of delimiters and line breaks, quotes, number of fields, encoding and data types (KOST). PDF/A holds only the appearance, not the calculation, and a conversion to PDF/A «must be judged very critically indeed» (KOST): as a view beside the original, not in its place.

Presentations: Preferred is ODP, like ODT and ODS; NARA prefers it, KOST rejects ODP for the same reasons as ODT. Where the slides are fixed, for instance for a talk given as it stands, the depositor had better also deliver PDF/A-2u. NARA rates PPTX low risk, KOST accepts it. LibreOffice reads Keynote only partly; the depositor exports it as PPTX or PDF.

In both cases the original stays the master. Anton does not convert at ingest.

Here too: an archive keeps as few formats as possible. The depositor delivers without password or write protection and switches off automatic updating of date fields.

Significant properties

Grouped as NARA does into appearance, structure, behaviour and context. The questions are the same as for text; for spreadsheets NARA also asks whether deleting a sheet changes the content.

Spreadsheets

Group Property Source
Appearance formatting where it conveys information (conditional formatting, colour coding) NARA
charts and graphics NARA
comments NARA
pivot tables NARA
Structure value of every cell NARA
sheets with their names NARA
number of rows and columns, hidden ones included NARA
character encoding and, for CSV, delimiter and escaping NARA, KOST
Behaviour formulas, where they explain how a value was calculated or a pivot table depends on them NARA, KOST
links within the file NARA
Context links to other files and data sources: recorded NARA

According to NARA, what counts first is the value in the cell, not the formula: «The final data in the cell itself is the core feature». The formula counts where it explains the value. Not to be preserved are macros and frozen rows or columns. Links to other files or to the web are recorded; the archive keeps their target only if it was delivered along.

Presentations

Group Property Source
Appearance slides and their order NARA
text, tables, images and graphics NARA
page size and orientation, fonts, colour, where the slides are fixed NARA
embedded audio and video NARA
Structure speaker notes NARA
outline NARA
Behaviour links within the file NARA
Context embedded metadata (title, author, dates, language) NARA

Speaker notes count when they hold what is not on the slides; that is often the case. Animations and transitions need not be preserved, as long as the slides are complete and legible without them (NARA).

What Anton measures and checks

As of version 0.111.1.

Property Measured Checked
Format PRONOM PUID with Siegfried, as for all files mismatch between extension, MIME type and PUID as a warning
Can be opened – only indirectly for presentations: LibreOffice must read them to make the access copy, which is validated like a PDF; for spreadsheets no
Text for full text: XLSX, ODS, PPTX, ODP and CSV directly, PPT from the PDF access copy; XLS not no
Character encoding and dialect (CSV) encoding, byte order mark, line endings, delimiter (comma, semicolon, tab, pipe) and number of fields in the first line, with libmagic at ingest –
all other properties no no

Limits

  • No access copy is made for spreadsheets; they appear as a download under «Other files». This is decided: a spreadsheet as PDF falls apart over many pages when sheets are wide, and does not show hidden rows.
  • For presentations (ODP, PPTX, PPT) LibreOffice makes a PDF access copy as for text (anton#719); they then appear under «Documents» in the PDF viewer. The copy shows the slides, not the speaker notes. A server without LibreOffice Impress makes none.
  • XLS does not reach the full-text index.
  • For CSV the delimiter is inferred: the one that splits the first line, quotes respected, into the most fields. It does not replace the depositor's description.
  • Whether a spreadsheet contains formulas, hidden rows, macros or links to other files, Anton does not measure.

What a migration must check

Anton has no rule yet that converts spreadsheets or presentations. When one comes, for instance XLS to XLSX, afterwards:

  • Spreadsheets: the value of every cell is the same, in all sheets; the number of sheets, rows and columns is the same, hidden ones included; formulas and comments are carried over.
  • Presentations: number and order of slides are the same; speaker notes and embedded media are carried over.
  • The embedded metadata is carried over.
  • The delivered file stays as an original.

Sources