Guidelines: Item Titles and Numbers

Every item in the BrickLink catalog has an assigned title and item number. These may be corrected by completing the Change Item form.

Item Titles:
Item titles are textual identifiers used in the reference catalog for searching and identification. Each item type uses different item titling as follows:
  • Sets - Sets are titled with the set name printed on the box. If no name is printed on the set box, then a title may be assigned as it appears in LEGO catalogs or on LEGO websites. If the set title is completely unknown, then a descriptive name is created and enclosed in braces/curly brackets {which look like this}. If multiple titles exist for the same set, then these are all included in the set title and separated by slashes.
  • Parts - Parts are titled first by type of part and then with the dimensions of the part. The title is usually a description of the part's shape and size.
  • Figures - Figures are titled first by occupation or role and then by character name if applicable. Additional text is then added to distinguish multiple versions of the same character. Figure titles should not include the item numbers of the items in which they appear.
  • Books - Books are titled according to the book title. Additional descriptive text may be used to distinguish versions.
  • Gear - Gear is titled using a LEGO catalog or website title or by using a descriptive name.
  • Catalogs - Catalogs are titled first with the year and then with the size. The title may then include the theme, the actual title of the catalog if it exists, and any identifying numbers.
Additional Notes About Titles:

  • Assumed Dimensions in Part Titles - When the height of a piece is standard for how that piece is categorized, then only two dimensions are used in the title. For example, bricks that are one brick high and plates that are one plate high have their height omitted from titles.
  • Axle Hole Orientation in Titles: - Parts that have holes designed to hold Technic axles sometimes have variants for which the orientation of the axle hole has been changed. Orientation is designated as either "+" (plus) or "x" (the letter x) and depends on how the axle tines appear with respect to studs on a part surface. A "+" orientation means an imaginary line extending from each axle tine would pass through the space between studs. An "x" orientation means an imaginary line extending from each axle tine would run into the studs.
  • Category Names in Titles - Category names in titles should not be used unless necessary to distinguish categories of parts. For example, there are categories titled Panel and Technic, Panel. Category names are included in part titles in both cases. Category names should also be used when titles would otherwise be nonsensical. In the category Brick, for example, Brick 1 x 1 would be a nonsensical title if the category title were removed. Category names may be shortened where appropriate.
  • Color Names in Titles - A color name should not be the first word or words in the part name. Sellers will select the color that will show as the first word or words in the part name when they list items for sale. Color names describing a design on a part should match the Color Guide names established for part materials as closely as possible. Color names should not be abbreviated unless absolutely necessary to fit an item title in the space allotted. Color names in item titles should be capitalized and punctuated as shown on the Color Guide page.
  • Commas in Titles - Comma usage in titles should be kept to an absolute minimum because it affects the way items are sorted by name, which is the default sorting method. The first comma or commas in item titles are included if necessary as part of the category name, but no commas are included immediately after the category name. After that, commas should be used only as necessary for reading comprehension.
  • Dimensions in Non-Brick Part Titles - Dimensions of some non-brick items are stated in metric units in the item name and the unit of measurement is given in the title. For example, electric wires are often measured in centimeters and their titles include the cm abbreviation for centimeters.
  • Dimensions in Slope Titles - Slopes include an approximation of the degree of the slope in their titles. Some common degrees are 33, 45, 65, and 75.
  • Dimensions in Wheel Titles - Numbers that look like dimensions in the titles of some wheels and tires, but which do not carry a measurement unit abbreviation, are not measurements. Such numbers are often molded into tires by the LEGO Group as decoration, but might also correspond with actual dimensions.
  • Left and Right Perspectives in Titles: - The terms left and right are applied from the forward-looking perspective of a figure itself and not from a human viewer looking at the figure. For vehicles the terms left and right indicate the perspective of the vehicle's driver.
  • Parentheses in Titles: - Parentheses may be used in titles to convey a variety of additional information. This information should typically be included at the end of the title. Titles should not include two sets of parentheses. Instead, the additional information should be arranged so that it fits into one set of parantheses.
  • Parts with Designs and their Titles - Parts with printed, stickered, or molded designs are titled by adding a description onto the base part's description and consistent descriptions should be used for similar patterns on different parts.
  • Restrictions on Titles: - Titles are limited to 150 characters and cannot include the double quotation mark character (").
  • Smooth Part Variant Titles: - The word "smooth" in a part name is used to distinguish a specific part variation. Over time the LEGO Group has changed the surface texture of some parts, notably slopes. In most cases the textured variety preceded the smooth variety. Smooth does not indicate a reduction of such surface textures to barely there. It indicates a surface completely and deliberately smooth except for accidental effects of the molding process.
  • Sticker Sheet Titles - Sticker sheets are titled "Sticker for Set" followed by the set number. If a set includes more than one sticker sheet, then ascending sequential numbers are added to the title to distinguish the sheets.
  • Trademarked Words in Titles: - If a trademarked LEGO word such as Dacta, Duplo, Friends, LEGO, Ninjago, Technic, etc. is the first word in an official item title, then that word is removed from the BrickLink title. This does not apply to trademarked words of other companies. BrickLink items are titled without trademarked LEGO words as the first word in a title because it causes items to sort improperly in the default view for search results.
  • Versions in Titles - Item titles may include information about the chronology of similar items. The earliest version of an item may include the words "1st Version" in the title, a later version may include "2nd Version" in the title, and so on. Other wordings of chronological information should not be used.


Item Numbers:
Item numbers are unique identifying numbers used in the reference catalog for searching and identification. Each item type uses different item numbering as follows:
  • Sets: - Items are numbered with the LEGO set number printed on the box or instruction manual for the set. The LEGO Group used some set numbers more than once. When adding a set with a duplicated set number use the next available sequential number (Set 1000-2, for example, if set 1001-1 is already in the catalog). If a set number is not printed on the set box or instructions, then descriptive text is used for the item number.
  • Parts: - Parts are numbered with the base part number, which is typically molded somewhere on the part and is either four or five digits. If a part number does not exist, then an initial capital letter P is used and followed by a five-digit sequential number which is increased by one for each new item added. Additional letters and numbers as shown below are then added to the base part number as necessary:
    • Variant Letter - Only used for different variants of the same part and used in alphabetical order by date. For example, the earliest part variant is lettered 1000a and a later variant is lettered 1000b.
    • Assembly Letter - Only used for parts which consist of two or more parts (part assemblies). The lowercase letter "c" is used for part assemblies and is followed by a two digit sequential number which is increased by one for each new item added.
    • Design Letter - Only used for parts with printed, stickered, or molded designs. The lowercase letter "p" is used for parts with designs and is followed by a four digit sequential number which is increased by one for each new item added.
  • Figures - Items are numbered with an initial capital letter F followed by a five-digit sequential number which is increased by one for each new item added.
  • Books: - Items are numbered with an initial capital letter B followed by a five-digit sequential number which is increased by one for each new item added.
  • Gear: - Items are numbered with an initial capital letter G followed by a five-digit sequential number which is increased by one for each new item added.
  • Catalogs: - Items are numbered with an initial capital letter C followed by a five-digit sequential number which is increased by one for each new item added.
Additional Notes About Item Numbers:

  • Alternate Item Numbers: - Alternate item numbers may be added to items. These may be the LEGO Group's original or additional identifying numbers, ISBNs or ISSNs, LEGO catalog numbers, BrickLink item numbers, package identification numbers, or any other item numbers deemed necessary for locating the item. These are entered in ascending numerical order and separated by a comma and a space. The alternate item number field is limited to 100 total characters.
  • Exceptions to Part Numbers: - For minifigure torso assemblies the design letter and sequential numbers are placed before assembly letter and sequential numbers. The first component of the assembly name refers to the pattern on the torso and the following components refer to colors of the arm and hand parts. For minifigure legs assemblies if the color of both legs is the same, but not same as the hip color, then the assembly letter is followed by a color ID. If the color of the legs and hips are the same, then the assembly letter is followed by the number 00. If the legs are in different colors or are not paired left and right leg parts, then an assembly letter of "d" is used.
  • Item Number Restrictions: - Item numbers are limited to 15 characters and can only contain letters (A-Z), numbers (0-9), Dash (-), Period (.), and Underscore (_).
  • Slashes in Set Item Numbers - Some older sets have a slash (/) in the item number and a period is used in place of the slash because having the slash in the item number would cause problems with links.
  • Sticker Sheets - A sticker sheet is assigned a number corresponding to the set in which it appears in the format 1000stk01 or 1000stk02. If two sets have the same number, then the set's sequential number will be reflected in the sticker number with a period. For example, 4032.1stk01 is a sticker for set 4032-1 and 4032.5stk01 is a sticker for set 4032-5.