HTML5 Constraint Attributes (CSV)
A flat table of the HTML5 constraint attributes: what each applies to, whether the browser enforces it, whether it blocks submission, and one valid and one invalid example. The spreadsheet-shaped twin of the JSON constraint rules.
attribute,applies_to,enforced_by_browser,blocks_submission,example_valid,example_invalid
required,most controls,yes,yes,any non-empty value,an empty string
pattern,textual inputs,yes,yes,NX-[0-9]{4},/NX-[0-9]{4}/
minlength,textual inputs,yes,yes,12,-1
maxlength,textual inputs,yes,no,280,0
min,numeric and temporal,yes,yes,2026-01-01,not-a-date
max,numeric and temporal,yes,yes,100,a value below min
step,numeric and temporal,yes,yes,0.01,0
type=email,input,yes,yes,person@example.com,person@
type=url,input,yes,yes,https://example.com,example.com
type=number,input,yes,yes,42,forty-two
accept,file,no,no,image/*,png
multiple,"email, file, select",partly,no,present,on a text input
autocomplete,most controls,no,no,shipping postal-code,postcode
inputmode,textual inputs,no,no,numeric,number
readonly,textual and numeric,yes,no,present,on a checkbox
disabled,all controls,yes,no,present,when the value must still be sent
novalidate,form,yes,no,present,on an input
formnovalidate,submit button,yes,no,present,on a text input
Specifications
- Rows
- 18
- Columns
- 6
- Header
- true
- Encoding
- UTF-8
What is a .csv file?
CSV (Comma-Separated Values) is a plain-text tabular format where rows are lines and fields are separated by commas, with quoting rules for values that contain delimiters, quotes, or newlines. It has no formal type system and depends on encoding and dialect conventions. It is the most portable format for tabular data exchange.
How to use this file
Use an example CSV to test parsers against quoting and embedded-delimiter edge cases, header handling, encoding detection, and import pipelines into databases or spreadsheets.
How to use this file for testing
“HTML5 Constraint Attributes (CSV)” is a deterministic Novus Examples fixture for Form parsing, Form testing, CSV parsing. PDF AcroForms with documented fields and live HTML forms for testing form parsers and fillers.
Documented properties for this file: 18 rows · 6 columns · UTF-8. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
This form is fictional SAMPLE content for tooling tests (autofill, scrapers, PDF fillers). It is not an official government, bank, or clinic form. Open the HTML offline or fill the PDF in any viewer; the demo submit path never stores data.
Code examples
import pandas as pd
df = pd.read_csv("html5-constraint-attributes.csv")
print(df.head())
print(df.dtypes)Related files
- csv10,000-Row CSVA CSV with 10,000 data rows — for testing streaming parsers, memory handling, and import performance.
- csvBidi Test-Case Matrix — eight rendering casesA flat index of the bidi cases in this wave — which mark each one uses, what it should render as, and why the neutral characters involved need help. Row b8 is the control case with no marks, against which the other seven are compared.
- csvBinary versus Decimal Arithmetic — Where Floats Disagree (.csv)Eight arithmetic expressions where binary floating point and exact decimal disagree, with both answers and the signed error side by side. Adding one cent a hundred times does not give one, and this file says by exactly how much.
- csvCalibration Certificate — Error and Expanded Uncertainty (.csv)Five calibration points with the nominal value, the measured value, the signed error and the expanded uncertainty at k=2 with its confidence level stated. It is a synthetic illustration of the layout, not an accredited certificate, and nothing in it refers to a real instrument or laboratory.
- csvCatastrophic Cancellation — Naive versus Stable Formulas (.csv)Five computations done twice, once with the obvious formula and once with the numerically stable one, with the relative error of the naive version alongside. The one-pass variance row is the memorable one: five values a millisecond apart near 1e8 can produce a negative variance.
- csvCensored Values and Detection Limits — Non-Numeric Results (.csv)Nine laboratory results where only four are plain numbers: two are below the detection limit, one is above range, two are missing in different spellings, and one is a legitimate small negative near the blank. Coercing the censored strings to numbers or to NaN both bias the summary, and the file distinguishes every case explicitly.
Generated by generation/forms_p7.py. Free for any use, no attribution required — license.