主层：以“1”表示

电荷层：以“q”表示

立体化学层：以“t”，“m”，“s”表示

异构体层（Isotopic layer）：以“i”表示

固定氢原子（Fixed-H layer）：以“f”表示

再连接层（Reconnected Layer）：以“r”表示

其中主层是必不可少的，其他的层是可以省略的。
子层
每个层都可以分成若干子层（sub-layer），比如主层可以分成以下三个子层：

分子式子层（没有前缀）

原子连接子层（以字母c开始）

氢原子层（以字母h开始）

InChIKey
InChIKey是InChI的雜湊函式，其长度为固定的27字符，适用于在数据库或网际网路中进行检索。其无法被直接解读为InChI明文。

举例
以维生素C的InChI为例：

该物质的InChIKey则为CIWBSHSKHKDKBQ-JLAZNSOCSA-N。

註釋
参见

SMILES

外部連結
文檔和演示文稿

[http://www.inchi-trust.org/ InChI Trust site]
[http://www.iupac.org/inchi/ IUPAC InChI site]
[http://wwmm.ch.cam.ac.uk/inchifaq/ Unofficial InChI FAQ]

[https://www.youtube.com/watch?v=mpZj4b9elYE&feature=gv]
[http://depth-first.com/articles/2006/08/12/inchi-canonicalization-algorithm Description of the canonicalization algorithm]
[http://lists.w3.org/Archives/Public/public-swls-ws/2004Oct/att-0019/ Googling for InChIs] a presentation to the W3C.
[http://video.google.com/videoplay?docid=5871900250712259806 The Semantic Chemical Web: GoogleInChI and other Mashups], Google Tech Talk by Peter Murray-Rust, 13 Sept 2006
[http://video.google.com/videoplay?docid=-6653695245776470969 IUPAC InChI], Google Tech Talk by Steve Heller and Steve Stein, 2 November 2006
[https://web.archive.org/web/20100330213717/http://www.iupac.org/inchi/release102final.html InChI Release 1.02] InChI final version 1.02 and explanation of Standard InChI, January 2009

軟件和服務

[http://cactus.nci.nih.gov/chemical/structure NCI/CADD Chemical Identifier Resolver] Generates and resolves InChI/InChIKeys and many other chemical identifiers
[http://www.chemspider.com/inchi%2Dresolver/ ChemSpider InChI resolver]
[https://web.archive.org/web/20060117153546/http://wwmm.ch.cam.ac.uk/gridsphere/gridsphere?cid=inchigoogle Search Google for molecules] (generates InChI from interactive chemical and searches Google for any pages with embedded InChIs). Requires Javascript enabled on browser
[http://www.acdlabs.com/download/chemsk.html ChemSketch], free chemical structure drawing package that includes input and output in InCHI format
[http://pubchem.ncbi.nlm.nih.gov/edit/index.html PubChem online molecule editor] that supports SMILES/SMARTS and InChI
[http://www.chemspider.com/Services.aspx? ChemSpider Services] that allows generation of InChI and conversion of InChI to structure (also SMILES and generation of other properties)
[https://web.archive.org/web/20070404073952/http://www.chemaxon.com/demosite/marvin/index.html MarvinSketch] from ChemAxon, implementation to draw structures (or open other file formats) and output to InChI file format
[http://bkchem.zirael.org/inchi_en.html BKchem] implements its own InChI parser and uses the IUPAC implementation to generate InChI strings
[http://www.compoundsearch.com CompoundSearch] implements an InChI and InChI Key search of spectral libraries
[http://jni-inchi.sourceforge.net/ JNI-InChI] Java library that wraps the InChI library
the Chemistry Development Kit uses JNI-InChI to generate InChIs, can convert InChIs into structures, and generate tautomers based on the InChI algorithms
Bioclipse generates InChI and InChIKeys for drawn structures or opened files

国际化合物标识