This is a tale of where @Bastien_Siebman’s beloved ideograms traded in their playful ways to punish the innocent! 
I’m sharing this tip because it got the best of me and required a bit of cleanup to undue the emoji mischief. The moral of this story is: If you are an avid user of the Asana CSV Importer, be sure that when adding emojis to the name of a Custom Field you UPDATE YOUR IMPORT TEMPLATE!
Personally, I like to make sure that the names of the columns in my CSV import file match the names of existing Custom Fields within the Project I am importing data to. For one, Asana does a great job of making sure the data is mapped to the correct field when doing so. This allows me to “Go to project” and not have to “Make Changes” (as seen below) allowing for the import process to begin right away. This can be quite rewarding when you repeatedly import project information using a standard file template.
In instances where the preview doesn’t seem correct and changes need to be made, having matching column names makes it easier for users to pinpoint any issues and correct accordingly.
Recently, I decided that I wanted to add an emoji to the beginning of two distinct Custom Fields to help differentiate between them. One represents a Box Link (web address) where the other is a Box Path (Windows File Path). Well… because I added an emoji to each, Asana didn’t associate the columns with these recently modified Custom Fields. Because changes were not made, new non-global Custom Fields were added to this Project (as seen below)
So now what? Emojis are so fun though! Have no fear. Simply copy the emoji into your CSV import template and Asana will get back to associating the columns that match existing Custom Field names (as seen below)
I know this is a minor detail, but perhaps one worth creating some awareness around. Especially for those that rely heavily on the CSV importer, like me. It is easy to get complacent when you doing something often enough that you have built a blind confidence to the process. Pay attention to the details and audit your processes on occasion to intercept long-term damages that tweaks like this could cause.
Asana on, my friends! 
