Sheet IDs and revision dates

Every ID has the same shape: the three letters FDS, a hyphen, and six characters drawn from a 32-character alphabet. That alphabet is the one Douglas Crockford proposed for base-32 identifiers: the ten digits and the capital letters, with I, L, O and U left out. Dropping those four removes the usual misreadings between I, L and 1 and between O and 0 when an ID is copied by hand or read aloud.

The six characters come from the sheet's URL slug, the last part of its address. The slug is run through a 32-bit FNV-1a hash, and five bits at a time of the result are written as one character of the alphabet. Six characters carry 30 bits, a little over a billion possible IDs, for a library of 174 sheets. At this revision the 174 sheets carry 174 distinct IDs, so no two share one.

Alphabet: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H J K M N P Q R S T V W X Y Z

One ID belongs to one presentation: a compound in one amount per vial, boxed in a stated number of vials. A different amount of the same compound is a different sheet with a different ID, even when everything else on the two sheets agrees. Where a compound is filed in several amounts, its substance sheet lists every amount with its ID.

The ID is Fara's reference for the datasheet. It is not a lot or batch number and carries no information about any particular box; it does not encode the price, the section or the date. Those are separate rows of the sheet, and they can change while the ID stays as it is.

It is also distinct from a CAS registry number. A CAS number identifies a substance wherever it appears and is the same on every amount of that substance (REF-01); a sheet ID identifies one sheet in this library and nothing outside it.

The revision date is printed in the title block of each sheet, in its footer, and in the plain-text catalog. It is the date, in UTC, on which the catalog record behind the sheet was last changed: a price, a presentation, a CAS number or another recorded field. A sheet with no recorded change date shows a dash.

A revision does not change the ID. Comparing the revision date on a saved copy with the one on the live sheet is therefore the quickest test of whether anything on the sheet may have moved since the copy was made. The date says that the record changed, not which field; the sheet itself shows the current values only.

Three fields are enough to identify the sheet that was read, and each is printed on the sheet itself:

1. the sheet ID, from the title block;
2. the revision date, beside it;
3. the URL, which the print layout adds to the footer of a paper or PDF copy.

For example: BPC-157 10mg, FDS-KM1E10, rev. 2026-09-25, farapeptides.com/compounds/bpc-157-10-milligram. A purchase record or inventory list that keeps those fields can be matched to the live sheet later, and the revision date shows at a glance whether the record has changed since.

The ID also works as a search term. The search on the compound list and the filter on the datasheet index both accept it, with or without the prefix. An email about a sheet is answered fastest when its subject line quotes the ID (DOC-07).

An ID establishes which sheet is meant; it says nothing about whether a compound can be ordered today, at what price, or in what quantity. Those are read from the sheet at the time of ordering, and the price that applies is the one shown when the order is placed. Nor does the ID describe the material: identity fields such as the CAS number, appearance and storage line appear only where the catalog record holds them (REF-05).