Hashtags & Attributes
Welcome to the start of our series of technical training videos on the Humanitarian Exchange Language. In this video, we focus on the building blocks of the HXL standard – hashtags and attributes. You will learn how to use hashtags and attributes to describe humanitarian data and some of the basic rules that you should follow when using the standard.
Key Takeaways
HXL hashtags label data columns and describe broad categories of data.
HXL hashtags identify the categories of data in each column of a humanitarian dataset. They’re data about data, or metadata.
HXL attributes refine the meaning of hashtags.
A HXL attribute is just like a hashtag, except that it starts with “+” instead of “#”, and always comes after the hashtag. HXL attributes do not carry complete information by themselves; they need to be combined with the thing they’re describing.
Add HXL tags between the header and the data.
While HXL uses hashtags to label columns of data, it still allows you to include human-readable headers. The headers go before the row containing the hashtags. The data starts in the next row. You can include up to 24 rows of headers before the HXL hashtag row.
The order of your attributes does not matter.
HXL attaches no significance to whitespace or attribute order. These are all exactly equivalent to HXL-aware software: #inneed +refugees +f +children and #inneed +f +children +refugees.
Feel free to leave data columns untagged.
It is not necessary to add HXL hashtags to every column. The HXL Working Group recommends tagging the columns that are most likely to be useful for interoperability with other humanitarian datasets, and also those that you would like to be able to use with HXL tools.
Create your own hashtags and attributes, as needed.
If you don’t find what you need in the core HXL hashtag and attribute dictionary, you can create your own hashtags starting with “x_”, such as #x_virulence or #x_risk. However, before you do so, please note that you may be able to use an existing hashtag and refine it using attributes, as described in the HXL standard.
Frequently Asked Questions
If no HXL hashtag is a perfect match, you still have a few options:
- You can use a more general hashtag combined with attributes, e.g. #affected +refugees +injured +elderly +f for the number of elderly refugee women injured.
- You can use the general #indicator hashtag combined with your own custom attribute to identify an indicator specific to your own organisation, project, or cluster, e.g. #indicator +facilities_damaged +num for the number of facilities damaged (where +facilities_damaged is the attribute that you created).
- If no general hashtag applies, you can create your own custom hashtag beginning with “x_”, e.g. #x_virulence for the virulence of a disease.
More information is available in the HXL standard, 3.2. Creating extension hashtags.
No. It is fine to leave some columns untagged, especially if they’re highly-specialised data that wouldn’t be of general interest. However, if the answer to any of these questions is “yes,” we strongly recommend tagging:
- Is the column important for connecting your data with related datasets (e.g. locations, dates, sectors, org names, population figures)?
- Do you want to be able to work on the data in the column using HXL-aware tools (transform, validate, visualise, search, etc)?
- Do you want to be able to operate on the data yourself, even if the column orders or headers change (e.g. importing into a database)?