I use the property "pages" for the number of pages of an article or book.
There are two problems.
First:
If I use C-c ^
to sort the items by the value of pages
org-sort
seems to interpret the numbers lexicographically: 1<100<20<3.
Of course I need the natural order of numbers: 1<3<20<100.
Second:
If I use C-c a m
to search for items with pages<20
I get
the correct items and the "wrong" items: where the pages
property is not defined.
How to ignore the "wrong" items?