Fields to send to Square app
On this screen you can pick what should be sent to Square in addition to total amount to pay.

The fields you pick here are pulled from the Taximeter receipt and appended to Square’s receipt note. Square exposes that single note field as the only way to pass custom text through.
Tip or discount
If you pick “Tip or discount” taximeter will send:
Tip $0.88
If there is a tip or discount or nothing, otherwise.
Receipt note
Tip $0.88. Note on receipt
Where “Receipt note” is what you’ve added as a note for the receipt in taximeter.
Fare detail
Tip $0.88. Note on receipt. Total distance 1.52mi, time 00:01:56. Fare: $3.00/mi $0.60/min. Minimum fare $4.00
Total extras
Tip $0.88. Note on receipt. Total distance 1.52mi, time 00:01:56. Fare: $3.00/mi $0.60/min. Minimum fare $4.00. Fare and extras total $5.12.
Fare note
Tip $0.88. Note on receipt. Total distance 1.52mi, time 00:01:56. Fare: $3.00/mi $0.60/min. Minimum fare $4.00. Fare and extras total $5.12. Included in entry fare: 1.0000 mi, until min mileage is reached throw the time charge away (max 1m0s). Waiting time at trip start 0m32s (waived 0m32s).Time waived during trip: 0m58s.
Start and end address
Tip $0.88. Note on receipt. Total distance 1.52mi, time 00:01:56. Fare: $3.00/mi $0.60/min. Minimum fare $4.00. Fare and extras total $5.12. Included in entry fare: 1.0000 mi, until min mileage is reached throw the time charge away (max 1m0s). Waiting time at trip start 0m32s (waived 0m32s).Time waived during trip: 0m58s. Start: Infinite Loop, Cupertino, CA, 95014, US. End: CA-85 N, Sunnyvale, CA, 95014, US
Square app limitations on receipt notes
Square records the full note it receives, but the email receipt it sends to customers is capped at just a few lines of text:

As you can see, Square truncates anything beyond a few lines in the email receipt — even though the full note remains on Square’s web transaction record:

Please take this note truncation into account when picking fields to transfer to Square. Over time, the length of note accepted by Square for email receipts may increase as well.