Fideslang stands for “Fides language” and is known to be the human-readable privacy taxonomy, designed to enable the standardized labeling of data elements in software development in a whole, and online advertising in particular.
What Is Fideslang?
Initially introduced by the privacy firm Ethyca, Fideslang is the open-source taxonomy for processing privacy data. In brief, it enables the unified, human-readable description and tagging of privacy-related data elements, data use cases and data subjects in order to simplify and streamline digital businesses’ compliance with ever-changing privacy laws and regulations worldwide.
In the online advertising context, the Fideslang initiative is consistent with the Privacy Taxonomy Project by IAB Tech Lab, felicitating the further standardization of privacy-related practices in the global digital ad tech industry.
What’s Inside
The Fideslang taxonomy implies the use of Data Categories, Data Uses and Data Subjects as labels to describe the type of Personal Data processed (e.g. demographic, behavior, device data, etc.), purposes of such processing (e.g. analytics, marketing, etc.) and the particular data owner type (e.g. employee, consumer, household, etc.), correspondingly.
Data tagging for Data Categories and Data Uses has a hierarchical structure, with data elements being labeled coarsely with the parent category (e.g. user.behavior for user behavior category, or marketing as the type of data use), or more precisely – through the use of sub-categories (e.g. user.behavior.media_consumption and marketing.advertising.serving, accordingly).
Meanwhile, Data Subject labeling has a so-to-speak flat structure, meaning that there are no subcategories implied for each data subject type (e.g. customer, anonymous_user, visitor, etc.), nor can a particular Data Subject include other Data Subjects.
Data Sensitivity
It’s crucial to assign a specific sensitivity score to each Data Category labeled, with “1” assigned to the non-sensitive data, “2” assigned to the data elements being perceived as sensitive only when used in combination with sensitive data points (e.g. login data) and “3” assigned to the sensitive data, as treated by the relevant privacy law/regulation.
Perspectives of Adoption
As Fideslang is designed to support all known privacy regulations, like CPRA and GDPR, and cross-references purposes of data use with the relevant IAB’s privacy initiatives, like TCF 2.0 and MSPA, the prospects of its adoption by the online advertising industry in 2025 and beyond are bright. However, it’s still unclear how much time the implementation process will actually take.