C23F1/00	7	Etching metallic material by chemical means (manufacture of printing surfaces B41C; manufacture of printed circuits H05K)	C23F1/00	C23F1/00		1128
C23F1/02	8	Local etching	C23F1/02	C23F1/02		2821
C23F1/04	9	Chemical milling	C23F1/04	C23F1/04		386
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		1681
C23F1/10	8	Etching compositions (C23F1/44 takes precedence)	C23F1/10	C23F1/10		219
C23F1/12	9	Gaseous compositions	C23F1/12	C23F1/12		350
C23F1/14	9	Aqueous compositions	C23F1/14	C23F1/14		403
C23F1/16	10	Acidic compositions (C23F1/42 takes precedence)	C23F1/16	C23F1/16		863
C23F1/18	11	for etching copper or alloys thereof	C23F1/18	C23F1/18		1760
C23F1/20	11	for etching aluminium or alloys thereof	C23F1/20	C23F1/20		937
C23F1/22	11	for etching magnesium or alloys thereof	C23F1/22	C23F1/22		145
C23F1/26	11	for etching refractory metals	C23F1/26	C23F1/26		1249
C23F1/28	11	for etching iron group metals	C23F1/28	C23F1/28		1223
C23F1/30	11	for etching other metallic material	C23F1/30	C23F1/30		980
C23F1/32	10	Alkaline compositions (C23F1/42 takes precedence)	C23F1/32	C23F1/32		184
C23F1/34	11	for etching copper or alloys thereof	C23F1/34	C23F1/34		290
C23F1/36	11	for etching aluminium or alloys thereof	C23F1/36	C23F1/36		558
C23F1/38	11	for etching refractory metals	C23F1/38	C23F1/38		221
C23F1/40	11	for etching other metallic material	C23F1/40	C23F1/40		320
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		1201
C23F1/46	8	Regeneration of etching compositions	C23F1/46	C23F1/46		1171
C23F3/00	7	Brightening metals by chemical means	C23F3/00	C23F3/00		570
C23F3/02	8	Light metals	C23F3/02	C23F3/02		166
C23F3/03	9	with acidic solutions	C23F3/03	C23F3/03		550
C23F3/04	8	Heavy metals	C23F3/04	C23F3/04		426
C23F3/06	9	with acidic solutions	C23F3/06	C23F3/06		852
C23F4/00	7	Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00	C23F4/00	C23F4/00		1362
C23F4/02	8	by evaporation	C23F4/02	C23F4/02		102
C23F4/04	8	by physical dissolution	C23F4/04	C23F4/04		92
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		800
C23F11/02	8	in air or gases by adding vapour phase inhibitors	C23F11/02	C23F11/02		924
C23F11/04	8	in markedly acid liquids	C23F11/04	C23F11/04		929
C23F11/06	8	in markedly alkaline liquids	C23F11/06	C23F11/06		297
C23F11/08	8	in other liquids	C23F11/08	C23F11/08		1956
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		2053
C23F11/12	10	Oxygen-containing compounds	C23F11/12	C23F11/12		220
C23F11/122	11	{Alcohols; Aldehydes; Ketones}	C23F11/12	C23F11/12		238
C23F11/124	11	{Carboxylic acids}	C23F11/12	C23F11/12		283
C23F11/126	12	{Aliphatic acids}	C23F11/12	C23F11/12		271
C23F11/128	11	{Esters of carboxylic acids}	C23F11/12	C23F11/12		112
C23F11/14	10	Nitrogen-containing compounds	C23F11/14	C23F11/14		350
C23F11/141	11	{Amines; Quaternary ammonium compounds}	C23F11/14	C23F11/14		530
C23F11/142	12	{Hydroxy amines}	C23F11/14	C23F11/14		177
C23F11/143	12	{Salts of amines}	C23F11/14	C23F11/14		247
C23F11/144	11	{Aminocarboxylic acids}	C23F11/14	C23F11/14		120
C23F11/145	11	{Amides; N-substituted amides}	C23F11/14	C23F11/14		320
C23F11/146	11	{containing a multiple nitrogen-to-carbon bond}	C23F11/14	C23F11/14		103
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		46
C23F11/149	11	{Heterocyclic compounds containing nitrogen as hetero atom}	C23F11/14	C23F11/14		1379
C23F11/16	10	Sulfur-containing compounds	C23F11/16	C23F11/16		393
C23F11/161	11	{Mercaptans}	C23F11/16	C23F11/16		155
C23F11/162	11	{Thioaldehydes; Thioketones}	C23F11/16	C23F11/16		61
C23F11/163	11	{Sulfonic acids}	C23F11/16	C23F11/16		137
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		220
C23F11/167	10	Phosphorus-containing compounds	C23F11/167	C23F11/167		215
C23F11/1673	11	{Esters of phosphoric or thiophosphoric acids}	C23F11/167	C23F11/167		231
C23F11/1676	11	{Phosphonic acids}	C23F11/167	C23F11/167		319
C23F11/173	10	Macromolecular compounds	C23F11/173	C23F11/173		825
C23F11/18	9	using inorganic inhibitors	C23F11/18	C23F11/18		512
C23F11/181	10	{Nitrogen containing compounds}	C23F11/18	C23F11/18		185
C23F11/182	10	{Sulfur, boron or silicon containing compounds}	C23F11/18	C23F11/18		210
C23F11/184	10	{Phosphorous, arsenic, antimony or bismuth containing compounds}	C23F11/18	C23F11/18		190
C23F11/185	10	{Refractory metal-containing compounds}	C23F11/18	C23F11/18		212
C23F11/187	10	{Mixtures of inorganic inhibitors}	C23F11/18	C23F11/18		287
C23F11/188	11	{containing phosphates}	C23F11/18	C23F11/18		219
C23F13/00	7	Inhibiting corrosion of metals by anodic or cathodic protection	C23F13/00	C23F13/00		248
C23F13/005	8	{Anodic protection}	C23F13/00	C23F13/00		245
C23F13/02	8	cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions	C23F13/02	C23F13/02		1037
C23F13/04	9	Controlling or regulating desired parameters	C23F13/04	C23F13/04		1058
C23F13/06	9	Constructional parts, or assemblies of cathodic-protection apparatus	C23F13/06	C23F13/06		1111
C23F13/08	10	Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto	C23F13/08	C23F13/08		241
C23F13/10	11	Electrodes characterised by the structure (C23F13/16 takes precedence)	C23F13/10	C23F13/10		610
C23F13/12	11	Electrodes characterised by the material (C23F13/16 takes precedence)	C23F13/12	C23F13/12		188
C23F13/14	12	Material for sacrificial anodes	C23F13/14	C23F13/14		581
C23F13/16	11	Electrodes characterised by the combination of the structure and the material	C23F13/16	C23F13/16		435
C23F13/18	11	Means for supporting electrodes	C23F13/18	C23F13/18		485
C23F13/20	11	Conducting electric current to electrodes	C23F13/20	C23F13/20		437
C23F13/22	11	Monitoring arrangements therefor	C23F13/22	C23F13/22		741
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		908
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		1200
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		395
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		100
C23F2213/11	9	for structures subject to stray currents	CPCONLY	C23F2213/11		57
C23F2213/20	8	Constructional parts or assemblies of the anodic or cathodic protection apparatus	CPCONLY	C23F2213/20		128
C23F2213/21	9	combining at least two types of anodic or cathodic protection	CPCONLY	C23F2213/21		109
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		593
C23F2213/32	9	Pipes	CPCONLY	C23F2213/32		683
