Across:
8 The gathering (The Gathering = SOCIAL) of nets from coastlines ('nets' from 'coastlines' = coasli = SOCIAL),
9 Cherub or (cherub or) bust (= anagram indicator) (cherub or = BROCHURE) in publicity booklet (BROCHURE),
10 Pen (female swan = SWAN) concealed by Miss Wannamaker (concealed by ‘misS WANnamaker’ = SWAN),
11 Exploit (MILK) prisoner (Prisoner-of-War = POW-) associated with the German (‘the’ German = -DER) (MILK POWDER) product that’s been preserved for brewers to consume (MILK POWDER),
12 Secure (OBTAIN) trip (= anagram indicator) in boat (in boat = OBTAIN),
14 Tense (tense) play (= anagram indicator) (tense = -SENTE-) taken in by Lincoln (Abe Lincoln = AB-E) (ABSENTEE) – The Man Who Wasn’t There? (ABSENTEE),
15 Refuse to move (STAND ONE’S GROUND) most of (s) those in 21 down (stands) (‘stands’ without ‘s’ = STAND), 23 down (‘ones’ = ONES) and 19 down (‘ground’ = GROUND) (STAND ONE’S GROUND),
18 Old Penny (old penny = D-) begged (begged) out (= anagram indicator) (begged = -EB-GGED) around university (-U-) (DEBUGGED) and cleaned-up around software department presumably (DEBUGGED),
20 Old (O-) American (-A-) swimmer (-FISH) (OAFISH) can be uncouth (OAFISH),
22 The type of subject that sticks in the mind (PSYCHOLOGY) or that’s the current thinking about the situation (PSYCHOLOGY)
24 Put up with (BEAR) closing time (closing ‘timE’ = -E-) in public house (bar = B-AR) (BEAR),
25 One of the options in laundering (PRE-RINSE) pounds (pounds) initially (‘pounds’ initially = P-) is about (-RE-) to dip (RINSE) (PRE-RINSE),
26 Peter out (RECEDE) with shrink? (RECEDE).
Down:
1 BBC owe (BBC owe) cast (= anagram indicator) (BBC owe = COBWEB) of Silk designed by those spinning yarns (COBWEB),
2 Banks long-term capital gain (banks ‘LOng-term capital gaIN’ = LION) for Big Cat (LION),
3 Old lover (flame) dumped sweetheart (‘swEet’ heart = ‘e’ + ‘flamE’ drops ‘e’ = FLAM-) with cutting (l) lingo? (‘lingo’ without ‘l’ = -INGO) (FLAMINGO) What a long-legged bird! (FLAMINGO),
4 The second son (ABEL = the second son of Adam and Eve) caught up (= reverse indicator) in Bible-bashing? (caught up in ‘bibLE-BAshing’ = leba = ABEL),
5 A number of pairs (couples) left out (‘l’) (‘couples’ without ‘l’ = COUPES) in a number of types of cars (COUPES),
6 Drama (SHOW-) in (-IN-) Government (-G) around (O-) party (Fianna Fáil = -FF) (SHOWING OFF) demonstrating exhibitionism (SHOWING-OFF),
7 Free rent? (free rent) Ground (= anagram indicator) (free rent = TREE FERN) for a plant with fronds! (TREE FERN),
13 Canon, nurse (canon nurse), butcher (= anagram indicator) (canon nurse = ANNOUNCERS), presenters? (ANNOUNCERS),
14 Change (AMEND) hols to get away from homelands (‘hols’ to get away from ‘homelands’ = meand = AMEND),
16 Estuary (estuary) flowing (= anagram indicator) (estuary = T-EASURY) around river (-R-) (TREASURY) presumably holds a number of deposits (TREASURY),
17 Local foolish person (goon = GOO- -N) consumes starter of duck (starter of ‘Duck’ = -D) and fish (ray) served up (= reverse indicator) (ray = YAR-) (GOOD YARN)? It’s a long story! (GOOD YARN),
19 Great (G-) selection of beers (-ROUND) (GROUND) to pitch (GROUND),
21 Gets up (STANDS) to top tables (top ‘Tables’ = -T-) in ocean liners (sands = S-ANDS)? (STANDS),
23 Individuals (ONES) in India abandoned by Indonesia (‘India’ abandoned by ‘Indonesia’ = ones = ONES),
24 Second (BACK) centre in rugby? (centre in rugby = BACK).