TOPIC: WAIVERG.R. No. L-17915 January 31, 1967TEOORO !. CA"TRO,petitioner and appellant,vs.A!AOELRO"ARIOa#Co$$%##%on&r o' C%(%) "&r(%*&, O!INAORA+TONAa#"&*r&,ary o' -%nan*&,!ELECIO R. O!INGO, a# Co$$%##%on&r o' In,&rna) R&(&nu&, an. TO!A" C. TOLEO,respondents and appellants.-ACT":This is a proceeding in quo warranto,certiorariand mandamus originally filed in the Court ofFirst Instanceof Manila. Thecontrovertedpositionisthat of Assistant Regional RevenueDirector II, Manila, whichbecaevacant onAugust !", #$%$, upontheprootionof itsoccupant, Alfredo &iene'. Respondent Toas C. Toledo was appointed in his place, and it isthis appointent that is being (uestioned by petitioner Teodoro M. Castro in this proceeding.I""/E:)hether the eight other Assistant Revenue Regional Directors waived their rights to the positionby their failure to coplain against Toledo*s appointent.R/LING:)aiver is the intentional relin(uishent of a +nown right. The silence of the eight other AssistantRevenueRegional Directorsdoes not aount toawaiver ontheir part. )aiver ust bepredicated on ore concrete grounds. The evidence ust be sufficient and clear to warrant afinding that the intent to waive is unista+able.Castro hiself, when he testified, could not categorically state that the eight others were notinterested in the position.,-ot having shown either seniority in ran+ aong the nine AssistantRevenue Regional Directors outside the Manila District or waiver on the part of those who weresenior to hi Castro has failed to establish a clear right to the office which would entitle hi tooust respondent Toledo.