Dynamic variables let you copy values from one variable to another without typing the full values multiple times in the image requests on your site.
A significant benefit of dynamic variables is the ability to capture long strings of data in multiple variables without actually passing the long string repeatedly. Some browsers limit the maximum length of HTTP GET requests (including the Adobe image request). Using dynamic variables ensures that all data is captured by reducing the length of the request to Adobe servers in cases where data is duplicated across several variables.
Let’s look at this example, the website https://www.bahn.de/
Did you notice that some eVars and Props have values with “D =” , such as c24 and v24，v47 and c57，which are dynamic values.
Let’s take an example and see how it is set. Suppose now I need to set the Page URL to a dynamic value.
We now create a Page URL for the data element, the specific settings are as follows:
Then go to Extensions, open Adobe Analytics Extension and find GLOBAL VARIABLES:
Props set as %Page URL%, here is the data element method for reference, detailed reference:10 Leveraging Data Elements for Tags Implementation. To create a dynamic variable, add a special prefix to the start of the value. The default prefix is “D=”，So eVar11 set as D=c11, D=c11 means captures the c11 value in eVar11.
Note: eVar11 and Props11 also need to be enabled in Adobe Analytics in order to receive data.
After publishing this, then let’s test it, open my blog, open the developer tools, and do the following:
Now you can see that the value of v11 is D = c11，But what you see in Adobe Analytics analysis is the same as c11.
The dynamic value may be a smaller amount of data sent to Adobe.