Bruce, I have never used flags. I have just been though the Therion book and wiki for information but for clarification could you post an example of surface flag use please.  

Thanks.

Nick

From: Therion [mailto:therion-bounces@speleo.sk] On Behalf Of Bruce Mutton via Therion
Sent: 09 May 2018 11:04
To: 'List for Therion users' <therion@speleo.sk>
Cc: Bruce Mutton <bruce@tomo.co.nz>
Subject: [Therion] Therion Map Header Overrides

Nick

>  The override below is to change the Therion default team, cave length, cave depth data on the map output. Used in this case because a short surface survey needed to be shown on the map but the data was skewing the actual cave length and depth.

I’m not sure that is a very good way to deal with the issue.

In the screenshot below I have a surface survey shown (green dots), designated surface by use of ‘flags surface’, ‘flags not surface’ interleaved with the survey data as appropriate.  No need to fudge the cave length or depth because Therion does not include surface data in the cave length. 

There is some complexity around it, but you can show or hide the cave and surface centrelines using;

  symbol-show group surface-centreline

  symbol-hide group cave-centreline

Bruce