Formatting a dataset
Finding out what format your users need your data in is the best approach to providing a data download. Depending on the size of your data, datasets can be provided as XLS or CSV. If you are looking to use a compressed version of a large amount of data, a CSV file is best for this – but bear in mind that CSV files are designed to be read by machines and do not allow any formatting.
Datasets should have a unique, lower case file name using dashes instead of spaces or underscores between words. File names should be short and concise. They should make it clear to the user what is included in the data download so that it makes sense out of context.
All dataset file names must be shorter than 218 characters or the file may not open for some users.
Creating the dataset
Datasets should be “marked up” as tables and the dataset title should be added in cell A1. The dataset title should follow house style, be front-loaded with the topic and include the geography, frequency and data period.
When creating your table make sure you:
- use a sans serif (tail-less) font, for example, Arial
- use at least size 10 font for body copy and at least size 12 for titles
- select the “automatic” colour
- avoid using italic text anywhere or bold text for the data
- avoid the use of cell borders on cells with lots of text in
- avoid highlighting text with a background fill
- check that all text is horizontal
- Use sensible tab names that are clear and concise, and fewer than 31 characters.
- Ensure the dataset file opens on the first tab to avoid confusion.
- Include contact details and the date of the next update on the first tab.
- Include a table of contents on the first tab in files that contain a lot of worksheets.
- Separate tables out onto individual worksheets for easy navigation.
- Remove blank tabs and extra spaces from the start or end of tab names.
- Use a simple table structure with clear headings and subheadings.
- Use clear and consistent titles across all tables for straightforward data usability.
- Do not split or merge cells as this affects accessibility.
- Do not hide or use blank rows or columns, instead adjust the column width and row height to create space.
- Give your tables one tagged header row. When marking up select “my table has headers” and make sure to write in your header.
- Wrap text within cells to make sure all text is visible and clearly spaced out.
- Avoid including images and charts.
- Do not use colour in a table to convey meaning that is not shown in another way, as this can make the text hard to read and distinguish from the background.
- Delete any blank worksheets.
- Avoid putting content below the table and having more than one table on a worksheet.
Cells with no data
When cells with no data are left empty it can make it difficult for users of assistive technology to work out where the table starts and ends.
Blank cells should not cause accessibility issues if:
- there is only one consistent reason a cell in a table may be left blank
- the table is marked-up correctly
- there is a note above the table, in a cell in column A, explaining that some cells are left blank and why
However, if there are several reasons a cell in a table may be left blank, you will need to describe why a cell has no data. Do not use symbols like full stops (..) or dashes (-). Instead, you should use the Government Statistical Service’s (GSS’s) harmonised guidance for Using symbols in tables. Put these in square brackets. If cells need to be left empty for more than one reason explain the reasons for this on the cover sheet.
Do not use “NA” to describe cells with no data. This shorthand is ambiguous, some may read it as “Not Applicable”, others may read it as “Not Available”.
You should include as much information as possible where it is needed. For example, when data is provisional or revised put the whole word in square brackets instead of using ‘[p]’ or ‘[r]’. If you need to use letters to avoid visual clutter make sure you include a key to explain them in column A.
Do not use superscript text or symbols. For more advice, see the Government Statistical Service’s guidance for more advice on how to use symbols in tables.
Signpost to detailed footnotes using the word “note” and a number in square brackets, for example: “[note 1]”. If a cell refers to more than one footnote you should list each in a separate pair of brackets, for example: “[note 1][note 2][note 3]”.
Always try to put note markers in table titles, column headings or row labels. If you need to mention notes for specific data points, you should add a notes column to the table, on the right. You should describe which cell or cells the note applies to, for example: “[note 1] This note applies to B10, C10 and D10”.
Put an explanation on the cover sheet highlighting where notes can be found and how note markers are presented, for example: “Some tables refer to notes. When notes are mentioned the note marker is presented in square brackets. The note text can be found in the notes table.”
We recommend creating a worksheet called “Notes” that contains a table listing all of the detailed notes for the spreadsheet.
Footnotes for a specific cell
If a note marker would not be useful in a title, column or row heading, you can create a “notes” column on the right side of the table. Here, you should describe which cell or cells the note applies to, for example: “[note 1] This note applies to B10, C10 and D10”.
Codes and symbols
- Use nationally recognised classifications, such as geography codes, and keep users updated with any changes to these where possible.
- If you are using symbols for communicating uncertainty, include a guide to explain to users what each of these mean.
- Add codes and symbols in a separate column to the data.
- Avoid using indentation to show geographic hierarchy.
The Government Analysis Function provides further detailed guidance on releasing statistics in spreadsheets.
Read more on best practice on dataset accessibility.
We are constantly improving based on research and best practice. Any significant changes to our guidance are available on the Updates page.