[NTG-context] font question re U+00336

[jbf]

I wonder if someone can help me interpret this message in the log file

fonts           > start missing characters: 
/home/jbf/bin/context/tex/texmf/fonts/opentype/public/tex-gyre/texgyrepagella-regular.otf
fonts           >   88  U+00336  ̶  COMBINING LONG STROKE OVERLAY
fonts           > stop missing characters

My questions are as follows:

1. What does 88 mean here? 88 instances of this missing glyph? Page 88? 
Or something else? or in other words, how might I discover where 
something is missing from the original text?

2. Tex Gyre Pagella is normally a pretty handy typeface to use for me 
because it has pretty much all the glyphs I normally need... except this 
one obviously! Isn't it really just an en rule (or very similar to 
such)? Or in other words, how do I best overcome the problem of this 
missing character?

3. And perhaps connected with the above question: is there good fallback 
solution one can use? Do I need to \definefontfallback something or is 
there an automatic one already happening?

I've started to examine the log files a bit more carefully for various 
items and it is showing up my ignorance!!

Julian