Yes it can be done, but your posted request lacks key details needed before I can accurately describe how to do this.
A summary field can show many different totals or subtotals depending in how it is placed on a layout or used in a calculation expression. So what does your summary field total?
All the records in your found set?
A subtotal that is displayed in a sub summary layout part?
A value from all the related records that pass a filter in a filtered portal?
A set of related records (no filtered portal)?
The summary field I have is just a count of the unique values within one field, which will never be greater than 10.
Sorry but that description could match any of the possible implementations that I described.
My best guess is that you have a layout and have placed this summary field in the footer or a trailing grand summary so that it shows this count based on all records in your found set.
Assuming that to be the case...
define a calculation field and select Number as the return type:
YourSummaryFieldHere > 1
make this an unstored calculation field if it does not automatically become one by referencing a summary field.
Put this field on your layout and format it with a check boxes format. Use a custom values value list with a single value: 1 in its value list.
That worked perfectly, a thousand thanks Phil!
Apologies on not being clearer on my requests, I'm still very new to the Filemaker world!
Hey this is a "newbie" forum in most respects so we expect the need to ask follow up questions and chase things "around the bush" a few times before all, Hopefully, becomes clear.
But one follow up note to keep in mind. That check box format will make it look like this is a field where you can edit this field. That might cause some confusion on the part of your users as they can trigger an error message if they click the check box. You can at least prevent that error message from appearing if you select this field and use the Behavior settings in the Inspector's Data tab to deny Browse Mode access.
You might also consider a different format that does not imply that the field can be edited.