Coding missing values in Royle point-count occupancy models

Thought this would be an easy problem to resolve but have turned up empty handed after a couple of searches on the forum and elsewhere. Apologies in advance if my search skills are lacking.
How do you code missing values in the Royle point-count occupancy models (OccupRNegBin or OccupRPoisson)? These models require count data and MARK reads in pairs of characters from 00 to 99 for each occasion (i.e., a count of 2 is coded 02). This is clearly described in the Donovan exercise 8 example
>?Donovan.8
However, how would missing values be coded in this paired format? I tried ".." and "." but with no luck. I did read in the forum that PRESENCE allows coding of missing values in the Royle point-count models, so I'm hoping that's the case with MARK and RMark?
Thanks for your help,
Andy
How do you code missing values in the Royle point-count occupancy models (OccupRNegBin or OccupRPoisson)? These models require count data and MARK reads in pairs of characters from 00 to 99 for each occasion (i.e., a count of 2 is coded 02). This is clearly described in the Donovan exercise 8 example
>?Donovan.8
However, how would missing values be coded in this paired format? I tried ".." and "." but with no luck. I did read in the forum that PRESENCE allows coding of missing values in the Royle point-count models, so I'm hoping that's the case with MARK and RMark?
Thanks for your help,
Andy