Less than symbol in formula causes error in calculated column when applying site design

Question

I'm producing a site design script for SharePoint Online in PowerShell using Add-SPOSiteScript as per these instructions, and I can create the script and add it to a site design without any errors. However, when I use this design to create a new SharePoint site, there is an error in two of my calculated columns in the List I'm creating. I've played around with the script a lot, and found that the root cause of this error is that these two calculated columns have formulas that contain a less-than character "<", and this results in the columns not being created from the design when the site is created.

In this instance I can reverse the logic of the formula so that I can instead use a greater-than symbol (which evidently works). However, what I want to know is, is there a way to escape the less-than character in the formula?

As an example, the following formula works, and a column is created when I use the site design:

"verb": "addSPFieldXml",
"schemaXml": "<Field Type=\"Calculated\" ResultType=\"Text\" Name=\"CalcProbability\" DisplayName=\"Probability\" Required=\"FALSE\"><Formula>=IF([Probability Value]=0.5,\"Rare\",\"Likely\")</Formula></Field>"

But if I use the formula below in the script (changing the equals symbol to less-than), the column fails to be created:

"verb": "addSPFieldXml",
"schemaXml": "<Field Type=\"Calculated\" ResultType=\"Text\" Name=\"CalcProbability\" DisplayName=\"Probability\" Required=\"FALSE\"><Formula>=IF([Probability Value]<0.5,\"Rare\",\"Likely\")</Formula></Field>"

The error I get in SharePoint online is:

The XML schema is invalid.

Once the site has been created, I can replace the formula with the original logic that uses the less-than character, so to me, this indicates that it could be a bug in the process of SharePoint Online applying the site-design to a site?

Or is this a known issue and there is a way to escape the less-than character in the formula?

Answer 1

Use < instead of less than symbol. You can try below:

 "verb": "addSPFieldXml",
 "schemaXml": "<Field 
 Type=\"Calculated\" 
 ResultType=\"Text\" 
 Name=\"CalcProbability\" 
 DisplayName=\"Probability\" 
 Required=\"FALSE\">. 
 <Formula>=IF([Probability Value]&lt;0.5,\"Rare\",\"Likely\")</Formula></Field>"