Creating a Keyword Dictionary


Custom Sensitive Information Types in Microsoft 365
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In this course, we look at how to create custom sensitive information types with tools like Exact Data Match classification, keyword dictionaries, and document fingerprinting.

Learning Objectives

  • Learn how to create and manage custom sensitive information types
  • Learn how to use the Exact Data Match classifier
  • Learn how to implement Document fingerprinting
  • Learn how to create and utilize a keyword dictionary

Intended Audience

  • This course is designed for anyone looking to keep their data safe within Microsoft 365 using sensitive information types



We have already talked about keyword lists earlier on in this course, but where do keyword dictionaries fall into the picture?

While keyword lists are an effective form of supporting elements within any sensitive information type, they are a bit more limiting than keyword dictionaries. Keyword lists are a bit restricted in terms of their size, while keyword dictionaries, in contrast, can contain a megabyte equating to roughly a million characters. An organization can choose to create a keyword dictionary using either Microsoft Purview compliance portal or Microsoft Purview compliance portal for PowerShell. Today, I'll be going through the online compliance portal. So, to start off, we need to open up Microsoft Purview and navigate to the data classification solution like we did in our earlier lecture. From here, we go to classifiers and sensitive info types and create a sensitive information type. We will follow a similar step-by-step process as our previous lecture by creating a new sensitive information type. 

So, we'll just give it a placeholder name and description and then click 'Next.' Just like before, we need to apply a pattern, so we click, 'Create' and go through the pattern tool. Now, a keyword dictionary can be a primary element or a supporting element, but for the demo, we'll just leave it as a primary. So, if I add the keyword dictionary as a primary element, it opens up the dictionary wizard where I can choose from existing dictionaries, upload my own dictionary, or create my own directly here in the wizard. To create my own, I simply type the name of the dictionary and then add the keywords just like I did with the keyword list. However, if I had a text document that I wanted to use rather than copying all the words into this wizard, I can click, 'Upload' and simply choose the document that houses the words. You can see once I choose the document, it automatically pulled all of those words into the tool. 

Once I verify this is correct, I simply follow the same steps I did in the earlier lecture and this is good to go. The nice thing about keyword dictionaries is that they're all saved and can be used for other sensitive information types as well. For example, if I wanted to add this dictionary to my employee ID sensitive information type we created earlier, I can very easily do that. I simply open up the employee ID information type, click 'Edit', and navigate the patterns. Now, I want to add this to the medium confidence level pattern, so I will click on the 'Edit' option here and can either add a new supporting element or edit its existing elements. Even though the keyword list and keyword dictionary I created have the same words in them, I'm just going to add the dictionary as well, just to showcase how to do it. In reality, I would most likely only use the dictionary. But since this is a demo, it doesn't really matter. 

So, I'll add supporting elements and choose keyword dictionary. Now, since we already created the dictionary, we don't need to upload or make another one. We can simply click on 'Choose From Existing' and choose the dictionary we had just created. Now, if you wanted to change this dictionary, you can simply add or remove words as you see fit within here. However, there are two very important things you need to remember when you do this with a keyword library. Firstly, when you change any keywords, it will also apply that to any other sensitive information type created using this dictionary. This means that if I deleted the word ID from this specific dictionary, then no other information type using this dictionary will have the word ID in there either. Second, you cannot change the name of a keyword dictionary from here. If you do change the name, it will not update the current dictionary, but rather create an entirely new keyword dictionary. As far as I'm aware, at this moment, there is no way to adjust the name of a keyword dictionary from the online Microsoft Purview tools, and this must be done using PowerShell. For more information on creating keyword dictionaries and modifying them, I have linked related documentation in the course materials section down below for you to review.


About the Author
Learning Paths

Lee has spent most of his professional career learning as much as he could about PC hardware and software while working as a PC technician with Microsoft. Once covid hit, he moved into a customer training role with the goal to get as many people prepared for remote work as possible using Microsoft 365. Being both Microsoft 365 certified and a self-proclaimed Microsoft Teams expert, Lee continues to expand his knowledge by working through the wide range of Microsoft certifications.