I'm not sure, but a potential place to have a look is within the EULA agreement. https://mkt.tableau.com/files/tableau_eula.pdf
Within here, I found a snippit for sample code, maybe this will suffice?
Thanks for this snippet, Jeff. But am not making any code changes or reproducing them. Am just wanting to use some images from Tableau online documentations like below one taken from https://onlinehelp.tableau.com/current/prep/en-us/help.html#prep_clean.html%3FTocPath%3D_____5 .
In essence, am just looking for approval/permission for using these images within my internal training document.
You may be best off asking your assigned account rep.