let me stress again, semi flexi and fully flexi is not only based on the difference on the withdrawal/redrawal part.

OCBC home loan is neither semi or fully flexi. It is a flexi package.

semi flexi package typically has these features:
1) requires you to phone in to indicate the extra payment as early settlement of advance payments
2) if you fail to indicate, you will be charged 1% (some banks do this afaik)
3) if you indicate advance payment, no additional interest is saved  as "advance" payment will only be credited to your loan account when it reaches your cycle date, so it is plain advance payments. and must be in multiple of your monthly payment.
4) For redrawable prepayments, you need to indicate separately and Redraw charge of RM50 is imposed (M*B charge Rm25)

full flexi:
1) current account tied to loan account
2) auto debit from current account at month end and interest is calculated based on outstanding balance minus amount in current account
3) maintenance charge of RM10 per month
4) setup/ processing fee of Rm200

OCBC home loan:
1) no need to call in whatsoever, all extra payments (of any amount) will go into your loan account and interest is saved immediately (exactly like fully flexi loans). you may pay 2/3 months in advance, no issue
2) no maintenance/ setup/ processing fee (you'll save a lot, brother...)
3) for redrawable prepayments, you can pump in cheque or direct over the counter.
4) Rm10 is charged for each redrawal and T+3 days processing time

In conclusion, everything in OCBC home loan is same as flexi loan, except for the redraw part and cheque book facility.

** To Chris Chew, yeah, absolutely interest is saved immediately... trust me... i am the expert...

It's not a reduction in principal balance, but who cares? Interest computation wise, it is going to be:

It's flexi loan, you save Interest.