Example: Change in frequency of updates 
What you discover when copy cataloging:
Frequency of updates stated on 'Introduction' page [viewed on Feb. 1, 2008] differs from frequency recorded in existing record for the database
Existing record created in February 1998:
Freq: f Regl: r
245 04 The EMBL reptile database ‡h [electronic resource]. 310 Updated semiannually 500 Title from home page (viewed on Feb. 8, 1998).