Challenge 2: Mismatched Column Names Without Match Fields — Solution Walkthrough

What happens without using Match Fields first:

Word's merge field list is built directly from whatever the ACTUAL
column headers in the connected Excel source are named — CustName,
AmtDue, Due_Date — not from some fixed, universal set of names it
expects. If merge fields are inserted using THOSE actual source
names, the merge would technically work correctly, since the fields
genuinely exist with those names. The real risk only appears if the
TEMPLATE was written assuming a different set of names (Name, Amount,
DueDate) — for example, the template was copied from a previous merge
project that used those names, or those exact field names were typed
in expecting Word to somehow know they mean the same thing as
CustName/AmtDue/Due_Date. In that case, «Name», «Amount», and
«DueDate» would not correspond to any actual column in THIS source at
all — Word either shows an error identifying the unrecognised field
name, or in some cases silently leaves that portion of the merge
blank, since there is no genuine automatic connection between
differently-worded field names without an explicit mapping step.

The correct fix:

Use Mailings > Match Fields to explicitly map Word's own standard
field roles (First Name, Last Name, Address, etc. — the built-in
role list Match Fields offers) onto whichever of the source's actual
columns (CustName, AmtDue, Due_Date) correspond to each one. Once
mapped, inserting a merge field via its Word-recognised role name
correctly pulls from the right source column regardless of what it's
actually called in the spreadsheet.

WHY THIS WORKS AS AN ANSWER
------------------------------
This is exactly the exact-match discipline this chapter compares
directly to XLOOKUP: Word cannot infer that "AmtDue" and "Amount"
refer to the same underlying concept on its own — an explicit mapping
step (Match Fields) is required to bridge that gap, the same way an
XLOOKUP's lookup value and the column it searches must match exactly,
with no fuzzy inference happening automatically on your behalf.