This field presents information and remarks concerning the edition/impression in question, including: 

1. concise identification of the edition/impression using relevant abbreviations or terms such as AFE, EFE, FFE, GFE, IFE, PFE, reprint, special impression, Titelauflage, lithographic transfer, number of subse­quent edition (ranging from second to sixth), etc.;[1]
   
2. actual or ostensible publication date or – in the case of the first impression – registration date, and the period of commercial availability.[2] 
   

Information about the following may also appear under ‘Comments’: 

• contents of albums and volumes, including TPs, dedication pages, half-titles, decorative lithography, por­traits and other ancillary elements (e.g. 15–1a-Sm, 32/1–1-Sam, MM–1-Sm, MM–1-Sam, MFM–1-SCH, 62/2–1a-BR, 64/1–1a-BR)
  
• colour of ink or range of colours present on the TP (e.g. 6–1-KI, 6–1a-KI, 43–2b-SCHU, HEX–1-HAt) or the colour of the paper (e.g. 1–1-BRZ, 5–1-BRZ)
  
• number of the given item within a series, as well as prices added to the TP either by hand or with a stamp (e.g. 1–1-SC, 1–1b-A&P, 2–1b-W, 6–1-W)
  
• absence of series or work numbers or of hand written/stamped prices (e.g. 1–1a-W)
  
• catalogue extracts which appear in all of the identified copies (e.g. 22–2a-B&H, 24–2a-B&H, 25/1-6(sep)–1c-B&H, 30–1c-B&H)
  
• defects in printing (e.g. 1–1a-HO, 6–1c-BR, 9–1c-KI, 11–1c-A&P, 23–1e-B&H, 25/1-6–1g-A&P, HEX–1b-Sam), in physical contents (e.g. 22–1a-Sm, 32–1a-Sm) or within the TP text itself (e.g. 9/3–1-W)
  
• textual material temporarily removed from but later restored to TPs (e.g. 2–1a-HAt, 2–1b-HAt, MEG–1a-CH)
  
• decorative features found either on TPs for which reproductions have not been provided (e.g. 2–2-HAt, 8–1a-KI, 32/1–1b-Sam) or within the music text (e.g. 30–1a-Sm, 43–1-SCHU, MFM–1-E, 74–1h-H)
  
• secondary pagination (e.g. 4–1b-COC, 25/1-6(sep)–1c-B&H, 67–1-Sam, 68–1-Sam)
  
• differences between the contents of copies classified under the same catalogue entry (e.g. 22–1c-BR, 33–1b-B&H). 
  

We also comment on other significant features of given copies (e.g. 1–1-BRZ, 10/2–0-Sm, 42–0-P) and on elements facilitating the identification of an edition and later reprints thereof (e.g. 5–1-HO, 5–1b-HO, 5–1c-HO, 5–1d-HO, 5–1e-HO, 5–1g-HO, 5–1h-HO, 7–4-KI, 7–5-KI, 10/1-6–2-KI, 10/1-6–3a-KI, 11–1-Sm, 18–1b-LE, 21–1b-B&H, 22–1-Sm, 27–1f-A&P, 32/2–2-Sam). 

Cross-references are given to other editions/impressions with identical or similar TPs (e.g. 1–1-SC, 6–1-W, 21–2a-B&H, 25/1-6–2a-B&H, 27/2–1g-A&P, 28/1-12–1-C, 34/1–1-B&H) and to catalogue entries describing the volumes in which works previously published in separate editions have been united (e.g. 32/1–2a-Sam, 32/1–2b-Sam, 32/1–3-Sam, 32/2–2-Sam, 32/2–3-Sam). We also provide cross-references when deducing the existence of an impression of which no copy has yet been located (e.g. 15–2f-B&H, 22–2-B&H, 26–3-B&H, 32/2–3-Sam, 37–1f-B&H), to indicate where supple­mentary information can be found about later reprints not described in the main body of the catalogue (e.g. 3–1a-ME, 70/2&69/2–1-W), and when discussing defective copies which pose problems of classification (e.g. 20–1c-W, 40–1a-W). 

Because the system of cross-references has been significantly revised (for details see ‘Cross-references, abbreviated descriptions, external and internal links’), the ‘Comments’ field in the online version of the catalogue provides one or more of the following: details of identical elements in impressions (e.g. 1–1a-HO, 1–1b-HO, 1–1c-HO, 2–1a-HAt, 2–1c-HAt, 2–1d-HAt); details of distinct ele­ments which might be used to identify them (e.g. 1–1a-W, 1–1a-BR, 2–2b-Sam); and sometimes both of these (e.g. 1–1d-HO, 2–1b-HAt, 2–2a-HAt).

[1] For further detail see the List of abbreviations. Definitions of these terms are provided in the Glossary.

[2] In cases where proposed publication dates are problematic, brief remarks to that effect are given in this field. For further information see Dating the editions.