[AccessD] Question re calculated text control on Report

MS Access 2003

The question concerns a calculated text control on a report that for
example primarily concatenates a number of "fields" including testing for
whether a "field" has any text, etc. etc.

I am re-visiting a report to make changes and see that none of the "fields"
referred to such a  calculated text control exist as text controls
themselves on the report.

The "fields" are columns from the report's record source query.

I seem to recall that in the past I have run into problems when the query
fields used on a calculated text control were not present as (hidden or
zero sized) text controls on the report.

A hidden text control would as an example have same name as the Control
Source
Name: LastName
Control Source: LastName

So what is best practice here?

a) ok to refer to query columns in the record source query on calculated
text controls

or

b) for query columns that we make reference to on a calculated text control
- always have them present on the report as (hidden or zero sized) text
controls themselves

??

What is really going on behind the scenes? I have always been unsure about
text controls having as name same name as the Control Source (the control
source being either a table column name or query column name)


/borge