Template:Isotopes/main/format-percent/format-number

1. remove prefix-[<≪]*

2. remove any suffix-% (NB suffix "%" is not required; % assumed anyway

3. check remaining value as number (bounce {{BaseConvert{{!}}10to10{{!}}number}})

4. WHEN not a number: return BLANK

5. rounds the number to 3 sigfig

6. dm: when n<0.01%, add prefix "<", when <0.001 add prefix "≪"

7. add suffix "%"

8. return

pattern: (<<≪)123.456( %) or (<≪)10e+6(%)

Other prefixes are not recognied (not "~", "ca.", ..); will return blank

FOR blank return, consider showing raw input:

{{if empty |1={{Isotopes/main/format-percent|raw-perc={{{raw-input|}}} }} |2={{{raw-input|}}} }}

Usage