C23F1/00	7	Etching metallic material by chemical means (manufacture of printing surfaces B41C; manufacture of printed circuits H05K)	C23F1/00	C23F1/00		1113
C23F1/02	8	Local etching	C23F1/02	C23F1/02		2787
C23F1/04	9	Chemical milling	C23F1/04	C23F1/04		379
C23F1/06	8	Sharpening files	C23F1/06	C23F1/06		71
C23F1/08	8	Apparatus, e.g. for photomechanical printing surfaces (photo- mechanical reproduction G03F)	C23F1/08	C23F1/08		1655
C23F1/10	8	Etching compositions (C23F1/44 takes precedence)	C23F1/10	C23F1/10		215
C23F1/12	9	Gaseous compositions	C23F1/12	C23F1/12		347
C23F1/14	9	Aqueous compositions	C23F1/14	C23F1/14		395
C23F1/16	10	Acidic compositions (C23F1/42 takes precedence)	C23F1/16	C23F1/16		852
C23F1/18	11	for etching copper or alloys thereof	C23F1/18	C23F1/18		1727
C23F1/20	11	for etching aluminium or alloys thereof	C23F1/20	C23F1/20		920
C23F1/22	11	for etching magnesium or alloys thereof	C23F1/22	C23F1/22		143
C23F1/26	11	for etching refractory metals	C23F1/26	C23F1/26		1227
C23F1/28	11	for etching iron group metals	C23F1/28	C23F1/28		1209
C23F1/30	11	for etching other metallic material	C23F1/30	C23F1/30		967
C23F1/32	10	Alkaline compositions (C23F1/42 takes precedence)	C23F1/32	C23F1/32		182
C23F1/34	11	for etching copper or alloys thereof	C23F1/34	C23F1/34		287
C23F1/36	11	for etching aluminium or alloys thereof	C23F1/36	C23F1/36		553
C23F1/38	11	for etching refractory metals	C23F1/38	C23F1/38		219
C23F1/40	11	for etching other metallic material	C23F1/40	C23F1/40		316
C23F1/42	10	containing a dispersed water-immiscible liquid	C23F1/42	C23F1/42		122
C23F1/44	8	Compositions for etching metallic material from a metallic material substrate of different composition	C23F1/44	C23F1/44		1188
C23F1/46	8	Regeneration of etching compositions	C23F1/46	C23F1/46		1155
C23F3/00	7	Brightening metals by chemical means	C23F3/00	C23F3/00		562
C23F3/02	8	Light metals	C23F3/02	C23F3/02		161
C23F3/03	9	with acidic solutions	C23F3/03	C23F3/03		544
C23F3/04	8	Heavy metals	C23F3/04	C23F3/04		418
C23F3/06	9	with acidic solutions	C23F3/06	C23F3/06		837
C23F4/00	7	Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00	C23F4/00	C23F4/00		1341
C23F4/02	8	by evaporation	C23F4/02	C23F4/02		102
C23F4/04	8	by physical dissolution	C23F4/04	C23F4/04		88
C23F11/00	7	Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent (adding inhibitors to mineral oil, fuels, or lubricants C10; adding inhibitors to pickling solutions C23G)	C23F11/00	C23F11/00		789
C23F11/02	8	in air or gases by adding vapour phase inhibitors	C23F11/02	C23F11/02		917
C23F11/04	8	in markedly acid liquids	C23F11/04	C23F11/04		916
C23F11/06	8	in markedly alkaline liquids	C23F11/06	C23F11/06		295
C23F11/08	8	in other liquids	C23F11/08	C23F11/08		1943
C23F11/10	9	using organic inhibitors<br><br><u>NOTE</u><br><br>A compound is classified in the last appropriate place.<br>Esters or anhydrides of organic acids are classified as the relevant acid unless otherwise indicated. Salts of a compound with an inorganic compound are classified as that compound unless specifically provided for.	C23F11/10	C23F11/10		2027
C23F11/12	10	Oxygen-containing compounds	C23F11/12	C23F11/12		215
C23F11/122	11	{Alcohols; Aldehydes; Ketones}	C23F11/12	C23F11/12		233
C23F11/124	11	{Carboxylic acids}	C23F11/12	C23F11/12		277
C23F11/126	12	{Aliphatic acids}	C23F11/12	C23F11/12		268
C23F11/128	11	{Esters of carboxylic acids}	C23F11/12	C23F11/12		112
C23F11/14	10	Nitrogen-containing compounds	C23F11/14	C23F11/14		349
C23F11/141	11	{Amines; Quaternary ammonium compounds}	C23F11/14	C23F11/14		521
C23F11/142	12	{Hydroxy amines}	C23F11/14	C23F11/14		175
C23F11/143	12	{Salts of amines}	C23F11/14	C23F11/14		246
C23F11/144	11	{Aminocarboxylic acids}	C23F11/14	C23F11/14		119
C23F11/145	11	{Amides; N-substituted amides}	C23F11/14	C23F11/14		317
C23F11/146	11	{containing a multiple nitrogen-to-carbon bond}	C23F11/14	C23F11/14		101
C23F11/147	11	{containing a nitrogen-to-oxygen bond}	C23F11/14	C23F11/14		113
C23F11/148	11	{containing a nitrogen-to-nitrogen bond}	C23F11/14	C23F11/14		45
C23F11/149	11	{Heterocyclic compounds containing nitrogen as hetero atom}	C23F11/14	C23F11/14		1361
C23F11/16	10	Sulfur-containing compounds	C23F11/16	C23F11/16		389
C23F11/161	11	{Mercaptans}	C23F11/16	C23F11/16		153
C23F11/162	11	{Thioaldehydes; Thioketones}	C23F11/16	C23F11/16		58
C23F11/163	11	{Sulfonic acids}	C23F11/16	C23F11/16		136
C23F11/164	11	{containing a -SO2-N group}	C23F11/16	C23F11/16		54
C23F11/165	11	{Heterocyclic compounds containing sulfur as hetero atom}	C23F11/16	C23F11/16		214
C23F11/167	10	Phosphorus-containing compounds	C23F11/167	C23F11/167		210
C23F11/1673	11	{Esters of phosphoric or thiophosphoric acids}	C23F11/167	C23F11/167		229
C23F11/1676	11	{Phosphonic acids}	C23F11/167	C23F11/167		314
C23F11/173	10	Macromolecular compounds	C23F11/173	C23F11/173		813
C23F11/18	9	using inorganic inhibitors	C23F11/18	C23F11/18		508
C23F11/181	10	{Nitrogen containing compounds}	C23F11/18	C23F11/18		180
C23F11/182	10	{Sulfur, boron or silicon containing compounds}	C23F11/18	C23F11/18		209
C23F11/184	10	{Phosphorous, arsenic, antimony or bismuth containing compounds}	C23F11/18	C23F11/18		188
C23F11/185	10	{Refractory metal-containing compounds}	C23F11/18	C23F11/18		207
C23F11/187	10	{Mixtures of inorganic inhibitors}	C23F11/18	C23F11/18		284
C23F11/188	11	{containing phosphates}	C23F11/18	C23F11/18		218
C23F13/00	7	Inhibiting corrosion of metals by anodic or cathodic protection	C23F13/00	C23F13/00		247
C23F13/005	8	{Anodic protection}	C23F13/00	C23F13/00		244
C23F13/02	8	cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions	C23F13/02	C23F13/02		1031
C23F13/04	9	Controlling or regulating desired parameters	C23F13/04	C23F13/04		1048
C23F13/06	9	Constructional parts, or assemblies of cathodic-protection apparatus	C23F13/06	C23F13/06		1092
C23F13/08	10	Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto	C23F13/08	C23F13/08		238
C23F13/10	11	Electrodes characterised by the structure (C23F13/16 takes precedence)	C23F13/10	C23F13/10		599
C23F13/12	11	Electrodes characterised by the material (C23F13/16 takes precedence)	C23F13/12	C23F13/12		183
C23F13/14	12	Material for sacrificial anodes	C23F13/14	C23F13/14		573
C23F13/16	11	Electrodes characterised by the combination of the structure and the material	C23F13/16	C23F13/16		431
C23F13/18	11	Means for supporting electrodes	C23F13/18	C23F13/18		482
C23F13/20	11	Conducting electric current to electrodes	C23F13/20	C23F13/20		427
C23F13/22	11	Monitoring arrangements therefor	C23F13/22	C23F13/22		724
C23F14/00	7	Inhibiting incrustation in apparatus for heating liquids for physical or chemical purposes (adding scale preventives or removers to water C02F5/00{; inhibiting incrustation in polymerisation reactors C23F15/005})	C23F14/00	C23F14/00		48
C23F14/02	8	by chemical means	C23F14/02	C23F14/02		521
C23F15/00	7	Other methods of preventing corrosion or incrustation	C23F15/00	C23F15/00		904
C23F15/005	8	{Inhibiting incrustation}	C23F15/00	C23F15/00		186
C23F17/00	7	Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25(coating for obtaining at least two superposed coatings either by methods not provided for in a single one of main groups C23C2/00 - C23C26/00, or by combinations of methods providedfor in subclasses C23C and C25D, C23C28/00)	C23F17/00	C23F17/00		1180
C23F2201/00	7	Type of materials to be protected by cathodic protection	CPCONLY	C23F2201/00		52
C23F2201/02	8	Concrete, e.g. reinforced	CPCONLY	C23F2201/02		391
C23F2213/00	7	Aspects of inhibiting corrosion of metals by anodic or cathodic protection	CPCONLY	C23F2213/00		1
C23F2213/10	8	Controlling or regulating parameters	CPCONLY	C23F2213/10		96
C23F2213/11	9	for structures subject to stray currents	CPCONLY	C23F2213/11		56
C23F2213/20	8	Constructional parts or assemblies of the anodic or cathodic protection apparatus	CPCONLY	C23F2213/20		125
C23F2213/21	9	combining at least two types of anodic or cathodic protection	CPCONLY	C23F2213/21		108
C23F2213/22	9	characterized by the ionic conductor, e.g. humectant, hydratant or backfill	CPCONLY	C23F2213/22		113
C23F2213/30	8	Anodic or cathodic protection specially adapted for a specific object	CPCONLY	C23F2213/30		135
C23F2213/31	9	Immersed structures, e.g. submarine structures	CPCONLY	C23F2213/31		588
C23F2213/32	9	Pipes	CPCONLY	C23F2213/32		668
