"Conditional" is going away. From the horse's mouth:
Thank you very much for contacting us in this context.
The term ‘conditional’ is provided on some ‘older’ approach charts.
The ‘CONDITIONAL’ is there to draw the operator’s attention to that fact so they will check the minimum box to see what those conditions are.
Occasionally the lowest DA(H)/MDA(H) is only available when certain conditions exist.
Some of the conditions which affect the availability of the lowest minimums may be a DME step-down fix, local or remote altimeter, day only minimums, or other special situations.
Taking a look at the KSRQ 13-2 for example, the condition to utilize the 540ft MDA is that the waypoint ANILY can identified (either by FMS or DME). If this cannot be accomplished, the aircrew would have to use the higher MDA.
The ‘conditional’ terminology is successively removed from our charts as we changed or (sic) production regulations to provide a ‘refer to minimums’ in such cases.
Best regards,
Charting Support Team
Advanced Navigation & Display Support