"Jim Macklin" wrote

If an altitude is underlined, it is the MINIMUM altitude...
if an altitude is over-lined it is the maximum altitude. If
it is both under and over-lined the altitude is mandatory.

Jim, you've really got to make a better attempt at keeping up
with these threads.

Garner Miller posted this a few days back:
1800 is the minimum altitude; that's why it's underlined only on the
bottom of the number on the NACO charts. If it were mandatory, it
would have lines above and below (or the word "Mandatory" on Jepp
charts), and you would have to go down to 1800.

Bob Moore