The Relational System - Mastering phpMyAdmin 2.8 for Effective MySQL Management - page 171

Choosing one of the values (by clicking either a key value or a description) closes this
window and brings the value back to the software_id column.
Referential Integrity Checks
We discussed the Operations sub-page and its Table maintenance section in
Chapter 10. If we have defined an internal relation for the authors table (a non-InnoDB
table), a new choice appears for the topics table: Check referential integrity :
A link (here, author_id -> authors.author_id ) appears for each defined relation, and
clicking it starts a verification. For each row, the presence of the corresponding key in
the foreign table is verified, and any errors are reported. If the resulting page reports
zero rows, this is good news!