The master template is {{Infobox element isotopes }} (talk ).
|name=
|symbol=
|isotopes=<!-- tablerow subtemplates, see below -->
|isotopes table footnote=
|conventional atomic weight=
|standard atomic weight=
|standard atomic weight ref=
Isotopes are to be entered by the editor in |isotopes=, using one subtemplate for each isotope. The subtemplate produces one row in the table (possibly with multiple decay mode routes). The infobox adds the outer table form.
What |isotopes= input should look like:
Main isotopes of <element>
| isotopes =<!-- the parameter -->
{{Infobox element isotopes/isotopes stable
| mn=19
| sym=F
| link=fluorine-19
| na=100%
}}<!-- a table datarow for one isotope -->
{{Infobox element isotopes/isotopes decay
| mn=251
| sym=Cf
| na=trace
| hl=898 y
| dm=α
| de=6.172
| pn=247
| ps=Cm
}}<!-- another table row for another isotope -->
Full demo input
The examples are from various elements.
| name=full demo
| conventional atomic weight=
| standard atomic weight=238.02891(3)
| standard atomic weight ref=<ref>Reference for ''A''<sub>r</sub></ref>
| isotopes table footnote=* = [[excited state]]{{sfn|Chisté|2006}}
| isotopes =
{{Infobox element isotopes/isotopes stable
| link=Fluorine-19
| mn=19
| sym=F
| na=100%
| n=10
}}
{{Infobox element isotopes/isotopes decay
| mn=251
| sym=Cf
| na=trace
| hl=898 y
| dm=α
| de=6.172
| link1=curium-247
| pn=247
| ps=Cm
}}
{{Infobox element isotopes/isotopes decay2
| mn=252
| sym=Cf
| na=trace
| hl=2.645 y
| dm1=α (96.91%)
| de1=6.217
| link1=curium-248
| pn1=248
| ps1=Cm
| dm2=SF (3.09%)
| de2=–
| pn2=
| ps2=–
}}
{{Infobox element isotopes/isotopes decay3
| mn=26
| sym=Al
| na=[[trace radioisotope|trace]]
| hl=7.17×105 y
| dm1=[[Positron emission|β<sup>+</sup>]]
| de1=1.17
| link1=magnesium-26
| pn1=26
| ps1=Mg
| dm2=[[electron capture|ε]]
| de2=–
| link2=magnesium-26
| pn2=26
| ps2=Mg
| dm3=[[Gamma radiation|γ]]
| de3=1.8086
| pn3=
| ps3=–
}}
{{Infobox element isotopes/isotopes_decay4
| mn=260
| sym=Md
| na=[[synthetic radioisotope|syn]]
| hl=31.8 [[day|d]]
| dm1=SF
| de1=–
| pn1=
| ps1=–
| dm2=α
| de2=7.000
| link2=einsteinium-256
| pn2=256
| ps2=Es
| dm3=ε
| de3=–
| link3=fermium-260
| pn3=260
| ps3=Fm
| dm4=[[beta emission|β<sup>−</sup>]]
| de4=1.000
| link4=nobelium-260
| pn4=260
| ps4=No
}}
