Sustainability (MDPI) Formatting Requirements: Complete Author Guide

Sustainability follows the standard MDPI abstract format, which is straightforward but has specific constraints.

• Word limit: 200 words maximum (150-word minimum recommended)
• Structure: Unstructured (single paragraph)
• Citations: Not allowed
• Abbreviations: Avoid unless universally understood (e.g., DNA, GDP)
• Keywords: 3 to 10 keywords required, listed immediately after the abstract

The abstract should summarize the background motivation in one sentence, describe the methods briefly, and present the main findings with specific quantitative results where possible. Don't end the abstract with a vague promise like "implications are discussed." State what those implications are.

Keywords should not duplicate words already in the title. MDPI's system uses keywords for indexing and discoverability, so choose terms that a researcher searching for your topic would actually type. Avoid overly broad keywords like "environment" or "sustainability" (the journal name already covers that).

A formatting detail specific to MDPI: keywords are separated by semicolons, not commas. Each keyword starts with a lowercase letter unless it's a proper noun. This small detail trips up authors coming from journals that use comma-separated, capitalized keywords.

Sustainability publishes online only, which means generous allowances for figures and tables. There's no strict limit on the number of display items.

Figure specifications:

Table formatting: MDPI uses a clean, minimal table style. Tables have a horizontal rule at the top, below the header row, and at the bottom. No vertical rules. No shading unless it serves a clear purpose (like highlighting specific cells in a data comparison). Table captions go above the table.

Figures should be submitted as separate high-resolution files in addition to being embedded in the manuscript. During the initial submission through the MDPI Submission System (SuSy), you'll upload figures both inline and as individual files.

A practical MDPI-specific detail: if your figure has multiple panels, label them (a), (b), (c) and define each in the caption. MDPI's production team is strict about figure panel labeling consistency. If your figure says "(A)" but your caption says "(a)," you'll get a correction request.

For maps, include scale bars and compass directions. MDPI's editorial office specifically checks cartographic figures for these elements.

Sustainability uses the MDPI reference style, which is a numbered sequential system shared across all MDPI journals.

In-text citations: Numbers in square brackets, assigned in order of first appearance. Multiple citations are separated by commas: [1,2,3] or as a range: [1-3]. Place the citation before the period at the end of a sentence.

Reference list format:

1. Author, A.B.; Author, C.D.; Author, E.F. Title of the Article. Journal Name Year, Volume, Page Range. https://doi.org/xxxxx

Key formatting details:

• Author names: Last Name, First Initial(s). Use semicolons between authors.
• List all authors (MDPI doesn't use "et al." in the reference list regardless of author count).
• Journal names are written in italics, not abbreviated.
• MDPI doesn't abbreviate journal titles. Write "Journal of Cleaner Production," not "J. Clean. Prod." This is a significant departure from most other publishers.
• DOIs are required for all entries that have them.
• For books: include publisher name and location (city, country).
• For web sources: include the full URL and the access date.

There is no formal cap on the number of references. Research articles typically cite 40 to 80 sources. Review papers regularly exceed 100 references without issue.

A common mistake with MDPI formatting: using abbreviated journal titles. If your reference management software (Zotero, Mendeley, EndNote) is set to abbreviate journal names, you'll need to switch it to full titles before generating your bibliography. The MDPI house style is explicit about this.

MDPI journals, including Sustainability, support supplementary materials that are published alongside the article as downloadable files.

Supported supplementary types:

• Additional figures and tables
• Extended datasets (Excel, CSV)
• Survey instruments and questionnaires
• Code and scripts
• Video and audio files
• Appendices that would interrupt the main text flow

Supplementary materials are cited in the main text as "Figure S1," "Table S1," etc. Each supplementary file needs a descriptive title and brief caption.

One important policy: MDPI supplementary materials undergo peer review along with the main manuscript. Reviewers have access to all supplementary files and are expected to evaluate them. Don't treat supplementary material as a dumping ground for low-quality content.

File size limits are generous (up to 60 MB per file for most formats). For datasets larger than this, MDPI encourages deposition in a public repository (like Figshare, Dryad, or Zenodo) with the DOI cited in the paper.

MDPI also supports a "Data Availability Statement" that must appear at the end of the manuscript, before the references. You need to specify where the data supporting your findings can be accessed, even if the answer is "available from the corresponding author upon request."

These are the details that experienced Sustainability authors know but newcomers miss:

Section structure is flexible. Unlike many journals that mandate IMRAD (Introduction, Methods, Results, and Discussion), Sustainability allows flexible section headings. Many published articles use custom sections like "Theoretical Framework," "Case Study," or "Policy Implications." The introduction should still appear, but subsequent sections can follow the structure that best serves your paper.

Author contributions statement. Mandatory for all articles with multiple authors. Must appear after the conclusions, using this exact format: "Conceptualization, A.B. and C.D.; methodology, A.B.; software, C.D.; validation, A.B., C.D. and E.F...." MDPI uses the CRediT taxonomy categories specifically.

Institutional Review Board (IRB) statements. If your research involved human subjects, you must include an "Institutional Review Board Statement" section. If it didn't, you still need the section, stating "Not applicable." MDPI editors check for this and will send the paper back if it's missing.

Informed consent statement. Same requirement as the IRB statement. Include it even if your paper is purely quantitative or computational. State "Not applicable" when relevant.

Conflicts of interest declaration. Mandatory. Must appear as its own section titled "Conflicts of Interest" (not "Competing Interests" or "Declaration of Interest"). If there are none, state "The authors declare no conflicts of interest."

Special issue considerations. A large proportion of Sustainability articles are published in Special Issues. If you're submitting to a Special Issue, your paper still goes through the same peer review process. The Guest Editor manages the review but doesn't bypass quality standards. However, Special Issue papers may have slightly more flexibility on topic scope compared to regular submissions.

No running headers. The MDPI template doesn't include running headers or footers in the manuscript. Don't add them manually. The production team adds these during typesetting.

Numbering. Sections use Arabic numerals (1., 1.1., 1.1.1., etc.). Don't use Roman numerals. Figures and tables are numbered sequentially throughout the paper, not by section.

1. Keywords use semicolons, not commas. This is the single most common formatting error in MDPI submissions. Separate keywords with semicolons.

1. Full journal names in references. Don't abbreviate. Write "Environmental Science and Technology," not "Environ. Sci. Technol."

1. Data Availability Statement is mandatory. Even if your data isn't publicly shared, you need this section.

1. All authors listed in references. MDPI doesn't use "et al." in the reference list, no matter how many authors a cited paper has. List every author.

1. Figure files submitted separately. Even though figures are embedded in the manuscript, you must also upload them as individual files through SuSy.