Across:
8 Order (DECREE) in residence disregards sin (“residence” disregards “sin” = redece = DECREE),
9 It’s said in passing (OBITUARY) for notice (death notice = OBITUARY),
10 Members of Metallica feeling (members of ‘metalliCA FEeling’ = CAFÉ) out of place promoting Hot Chocolate (CAFE),
11 Keeps things tight and under control (RUBBER BAND) opening 6 down (opening ‘rubber tree’ = RUBBER) for musical group (BAND) (RUBBER BAND),
12 Old capital (two shillings = FLORIN) of Ulster (NI = -IN) with function (role) briefly (e) (‘role’ briefly = rol = -LOR-) to offend (‘ofF’ end = F-) going all the way back (= reverse all indicator) (FLORIN),
14 In retrospect (= reversal indicator), small (-G) march (mar = -RAM-) is great (-G-) for backing (backing/aid = DIA-) (DIAGRAMS) representations (DIAGRAMS),
15 Growing business (farm = FAR -M) includes heads of Friesians, reindeers, oxen? (heads of ‘Friesians Reindeers Oxen’ = FRO-) Article (THE), in fact (TRUTH) (FAR FROM THE TRUTH), implies a cock and bull story! (FAR FROM THE TRUTH),
18 Building (= anagram indicator) for sale (for sale = AL FRES-O) around castle (-C-) (AL FRESCO) outside (AL FRESCO),
20 Moral values (IDEALS) of ladies’ (ladies) movement (= anagram indicator) (ladies = IDEALS),
22 Principal (MAIN) with links (golf links COURSE) (MAIN COURSE) to one of those coming out of the kitchen (MAIN COURSE),
24 Crept off red carpet (‘crept’ off ‘red carpet’ = reda = READ) in study (READ),
25 Type of bottle (SCREW TOP) that’s not made in Cork (SCREW TOP not made in cork),
26 Not the first (‘Not’ the first = -N-) consumed by basic (basic) training (= anagram indicator) (basic = CABI-S) (CABINS) in mountain retreats (CABINS).
Down:
1 For a memorable time (-ERA-) on island (-I-) in Donegal (D-L) (DERAIL), lose track of one of them online? (DERAIL train on line),
2 One of those in The Cherry Orchard (TREE) closes 6 down (‘closes ‘rubber tree’ = TREE),
3 Verbally attack (TEAR INTO) Split (TEAR) Teachers’ Group (Irish National Teachers’ Organisation = INTO) (TEAR INTO),
4 If you’re not aware 9 across (obituary) is about you, it might be because you’re in here? (TOMB) And, that’s grave! (TOMB),
5 Mine (mine) engineer (= anagram indicator) (mine = -INEM-) in California (C-A) (CINEMA) is looking to show 19 down (“shorts” films) to an audience (CINEMA),
6 Pat (RUB-), Bert (Bert = BER T-) and Holly (tree) losing the head (t) (‘tree’ without ‘t’ = -REE) (RUBBER TREE) with latex producer (RUBBER TREE),
7 Broadcast (TRANSMIT) of martins (martins = TRANSMI-) flying (= anagram indicator) near square (-T square) (TRANSMIT),
13 Mentions (REFERENCES) they say things about some peoples’ characters (REFERENCES),
14 It’s been said before (DITTO) – dictators don’t have cars? (“dictators” don’t have “cars” = ditto = DITTO)
16 Russell (George William Russell = AE = A-E) welcomes lines (-LL-) to one (-I-) party (African National Congress = -ANC-) (ALLIANCE) in coalition (ALLIANCE),
17 What the witness produced at the bar perhaps (EVIDENCE) for The Confirmation (EVIDENCE),
19 Oral stimulants (SHORTS) for boxers? (SHORTS),
21 Picks up (LEARNS) widowers out of world-weariness (‘widowers’ out of ‘world-weariness’ = rlanes = LEARNS),
23 Upsets (= reversal indicator) Pole on ship (mast pole = spar = RAPS) with musical tunes (RAPS),
24 Wedding celebration (40th wedding anniversary = RUBY wedding) in one of the ports (RUBY port).