Quotations reference: viewtopic.php?p=214815#p214815
What do you mean with "weaker" ?
Your descriptions a la Sekiguchi Harutoshi of J1989 Rules style playing-under-the-stones or not being able to do so because of forbidden suicide points is weaker than my J2003 Rules v35a desciption by local-2 and capturable-2 because of these reasons:
- missing fundamental definitions, such as hypothetical-sequence, hypothetical-strategy and force,
- missing reference to applicable rules, such as hypothetical-ko,
- missing definition of a locale, such as local-2,
- missing clarification that what can be forced is not necessarily "filling an intersection that is a forbidden for the opponent" but is "playing-under-the-stones OR filling an intersection that is a forbidden for the opponent" (if you do not want playing a local-2 permanent-stone).