Yes. You would need some kind of field in your records to identify those records. For exampe a field name hiderecord then set T or F, and then add a condition to your relationship that is used in your portal : and hiderecord = F . This will leave all record with a T out of your portal.
There are two basic approaches:
A relationship based conditional value list can be used if you set up a relationship that only matches to the records you want to use for your value list--what S Chamblee has referred to.
Or set up a calculation field that is empty for the records you don't want in your value list but returns the value you need for your value list if it is one of the records you need for your value list and then you set up your value list to refer to this field instead of the original value field.
Option 1 can be more flexible, but requires adding the appropriate relationship--often whith a constant value match field defined in the parent table to use in the relationship to match to the correct set of related records. (This option is more flexible in that you can use different methods to control whether or not the seldom selected values are included or excluded from the list or can even appear in place of the normal list of items.)
Option 2 does not require a relationship and thus is slightly simpler to set up, but is a bit less flexible an option.
With either method, you'll need a field in your products table where a specific value identifies which records provide values to the value list.
Thank you both - Used option 2 and iot works perfectly...